diff --git a/src/app/[handle]/[collection]/[rkey]/page.tsx b/src/app/[handle]/[collection]/[rkey]/page.tsx
index ed8e1e5..a3b85e7 100644
--- a/src/app/[handle]/[collection]/[rkey]/page.tsx
+++ b/src/app/[handle]/[collection]/[rkey]/page.tsx
@@ -10,6 +10,7 @@ import Header from '@/components/Header';
 import { parseURI, resolveHandle, getDisplayName } from '@/utils/uriParser';
 import { fetchRecordData } from '@/utils/recordFetcher';
 import { resolveDidToHandle } from '@/utils/didResolver';
+import { getPostOgImage } from '@/utils/postOgImage';
 import { getMarginLexiconType, getMarginLexiconDisplayName, getMarginLexiconDescription } from '@/utils/marginLexicons';
 import {
   MarginAnnotationPreview,
@@ -70,6 +71,24 @@ export async function generateMetadata({ params }: Props): Promise<Metadata> {
           ? author.avatar.replace('/img/avatar/', '/img/avatar_thumbnail/')
           : '';
 
+        // Prefer the post's embedded media (photo/video/external thumb) so
+        // rich-link previewers (iMessage, Twitter, Slack, etc.) render the
+        // large image like bsky.app does. Fall back to the avatar thumbnail
+        // for text-only or quote-only posts.
+        const postOgImage = getPostOgImage(post);
+        const ogImage = postOgImage
+          ? {
+              url: postOgImage.url,
+              ...(postOgImage.alt ? { alt: postOgImage.alt } : {}),
+              ...(postOgImage.width && postOgImage.height
+                ? { width: postOgImage.width, height: postOgImage.height }
+                : {}),
+            }
+          : avatarThumb
+          ? { url: avatarThumb }
+          : null;
+        const twitterCard = postOgImage ? 'summary_large_image' : 'summary';
+
         const canonicalUrl = `https://aturi.to/profile/${author.handle}/post/${rkey}`;
         const atUri = `at://${resolvedDid}/${collection}/${rkey}`;
         const oembedUrl = `https://aturi.to/api/oembed?format=json&url=${encodeURIComponent(atUri)}`;
@@ -96,13 +115,13 @@ export async function generateMetadata({ params }: Props): Promise<Metadata> {
             url: canonicalUrl,
             siteName: 'Aturi',
             ...(publishedTime ? { publishedTime } : {}),
-            ...(avatarThumb ? { images: [{ url: avatarThumb }] } : {}),
+            ...(ogImage ? { images: [ogImage] } : {}),
           },
           twitter: {
-            card: 'summary',
+            card: twitterCard,
             title: authorByline,
             description: postText || postDescription,
-            ...(avatarThumb ? { images: [avatarThumb] } : {}),
+            ...(ogImage ? { images: [ogImage.url] } : {}),
           },
           other: {
             'profile:username': author.handle,
diff --git a/src/app/profile/[handle]/post/[rkey]/page.tsx b/src/app/profile/[handle]/post/[rkey]/page.tsx
index ff3d620..07c7a4a 100644
--- a/src/app/profile/[handle]/post/[rkey]/page.tsx
+++ b/src/app/profile/[handle]/post/[rkey]/page.tsx
@@ -9,6 +9,7 @@ import Header from '@/components/Header';
 import { parseURI, resolveHandle, getDisplayName } from '@/utils/uriParser';
 import { fetchRecordData } from '@/utils/recordFetcher';
 import { resolveDidToHandle } from '@/utils/didResolver';
+import { getPostOgImage } from '@/utils/postOgImage';
 
 type Props = {
   params: Promise<{ handle: string; rkey: string }>;
@@ -54,6 +55,24 @@ export async function generateMetadata({ params }: Props): Promise<Metadata> {
         ? author.avatar.replace('/img/avatar/', '/img/avatar_thumbnail/')
         : '';
 
+      // Prefer the post's embedded media (photo/video/external thumb) so
+      // rich-link previewers (iMessage, Twitter, Slack, etc.) render the
+      // large image like bsky.app does. Fall back to the avatar thumbnail
+      // for text-only or quote-only posts.
+      const postOgImage = getPostOgImage(post);
+      const ogImage = postOgImage
+        ? {
+            url: postOgImage.url,
+            ...(postOgImage.alt ? { alt: postOgImage.alt } : {}),
+            ...(postOgImage.width && postOgImage.height
+              ? { width: postOgImage.width, height: postOgImage.height }
+              : {}),
+          }
+        : avatarThumb
+        ? { url: avatarThumb }
+        : null;
+      const twitterCard = postOgImage ? 'summary_large_image' : 'summary';
+
       const canonicalUrl = `https://aturi.to/profile/${author.handle}/post/${rkey}`;
       const atUri = `at://${resolvedDid}/${collection}/${rkey}`;
       const oembedUrl = `https://aturi.to/api/oembed?format=json&url=${encodeURIComponent(atUri)}`;
@@ -80,13 +99,13 @@ export async function generateMetadata({ params }: Props): Promise<Metadata> {
           url: canonicalUrl,
           siteName: 'Aturi',
           ...(publishedTime ? { publishedTime } : {}),
-          ...(avatarThumb ? { images: [{ url: avatarThumb }] } : {}),
+          ...(ogImage ? { images: [ogImage] } : {}),
         },
         twitter: {
-          card: 'summary',
+          card: twitterCard,
           title: authorByline,
           description: postText || description,
-          ...(avatarThumb ? { images: [avatarThumb] } : {}),
+          ...(ogImage ? { images: [ogImage.url] } : {}),
         },
         other: {
           'profile:username': author.handle,
diff --git a/src/utils/postOgImage.ts b/src/utils/postOgImage.ts
new file mode 100644
index 0000000..b6ba5a6
--- /dev/null
+++ b/src/utils/postOgImage.ts
@@ -0,0 +1,87 @@
+/**
+ * Extract the best preview image from a Bluesky post for use as og:image.
+ *
+ * When a post has an image, video, or external-link embed we want rich-link
+ * previewers (iMessage, Twitter, Slack, etc.) to render that media as the
+ * large card image — same as bsky.app does. Without this, all aturi post
+ * links fall back to the author's small avatar thumbnail.
+ */
+
+import type { BskyPost } from './recordFetcher';
+
+export type PostOgImage = {
+  url: string;
+  alt?: string;
+  width?: number;
+  height?: number;
+};
+
+type EmbedView = {
+  $type?: string;
+  images?: Array<{
+    thumb?: string;
+    fullsize?: string;
+    alt?: string;
+    aspectRatio?: { width: number; height: number };
+  }>;
+  external?: {
+    thumb?: string;
+    title?: string;
+  };
+  thumbnail?: string;
+  alt?: string;
+  aspectRatio?: { width: number; height: number };
+  media?: EmbedView;
+};
+
+function pickFromView(view: EmbedView | undefined): PostOgImage | null {
+  if (!view) return null;
+
+  if (
+    view.$type === 'app.bsky.embed.images#view' &&
+    view.images &&
+    view.images.length > 0
+  ) {
+    const img = view.images[0];
+    const url = img.fullsize || img.thumb;
+    if (!url) return null;
+    return {
+      url,
+      alt: img.alt,
+      width: img.aspectRatio?.width,
+      height: img.aspectRatio?.height,
+    };
+  }
+
+  if (view.$type === 'app.bsky.embed.video#view' && view.thumbnail) {
+    return {
+      url: view.thumbnail,
+      alt: view.alt,
+      width: view.aspectRatio?.width,
+      height: view.aspectRatio?.height,
+    };
+  }
+
+  if (view.$type === 'app.bsky.embed.external#view' && view.external?.thumb) {
+    return {
+      url: view.external.thumb,
+      alt: view.external.title,
+    };
+  }
+
+  return null;
+}
+
+export function getPostOgImage(post: BskyPost): PostOgImage | null {
+  const embed = post.embed as EmbedView | undefined;
+  if (!embed) return null;
+
+  const direct = pickFromView(embed);
+  if (direct) return direct;
+
+  if (embed.$type === 'app.bsky.embed.recordWithMedia#view') {
+    return pickFromView(embed.media);
+  }
+
+  return null;
+}