@dansup I believe Robb explained the bug to me as the RSS feed only lists one photo(first photo that's shown on Pixelfed) and doesn't even list that the post has any other photos, which is why when it's shared to other platforms with something like EchoFeed or anything similar, it will only ever show one photo.
I feel like this effects tons of users who use services like EchoFeed and others to post their Pixelfed posts to other places.