Show just first image if we receive mixed multi-attachment msg

ts/components/conversation/ImageGrid.md

@@ -352,3 +352,35 @@ const attachments = [
   </div>
 </div>;
 ```
+
+### Mixing attachment types
+
+```
+const attachments = [
+  {
+    url: util.pngObjectUrl,
+    contentType: 'image/png',
+    width: 320,
+    height: 240,
+  },
+  {
+    contentType: 'text/plain',
+  },
+  {
+    url: util.pngObjectUrl,
+    contentType: 'image/png',
+    width: 320,
+    height: 240,
+  },
+];
+
+<div>
+  <div>
+    <ImageGrid attachments={attachments} i18n={util.i18n} />
+  </div>
+  <hr />
+  <div>
+    <ImageGrid withContentAbove withContentBelow attachments={attachments} i18n={util.i18n} />
+  </div>
+</div>;
+```

ts/components/conversation/ImageGrid.tsx

@@ -50,7 +50,7 @@ export class ImageGrid extends React.Component<Props> {
       return null;
     }
 
-    if (attachments.length === 1) {
+    if (attachments.length === 1 || !areAllAttachmentsVisual(attachments)) {
       const { height, width } = getImageDimensions(attachments[0]);
 
       return (
@@ -324,6 +324,13 @@ export function isImage(attachments?: Array<AttachmentType>) {
   );
 }
 
+export function isImageAttachment(attachment: AttachmentType) {
+  return (
+    attachment &&
+    attachment.contentType &&
+    isImageTypeSupported(attachment.contentType)
+  );
+}
 export function hasImage(attachments?: Array<AttachmentType>) {
   return attachments && attachments[0] && attachments[0].url;
 }
@@ -374,6 +381,22 @@ function getImageDimensions(attachment: AttachmentType): DimensionsType {
   };
 }
 
+function areAllAttachmentsVisual(attachments?: Array<AttachmentType>): boolean {
+  if (!attachments) {
+    return false;
+  }
+
+  const max = attachments.length;
+  for (let i = 0; i < max; i += 1) {
+    const attachment = attachments[i];
+    if (!isImageAttachment(attachment) || !isVideoAttachment(attachment)) {
+      return false;
+    }
+  }
+
+  return true;
+}
+
 export function getGridDimensions(
   attachments?: Array<AttachmentType>
 ): null | DimensionsType {