The source project of this merge request has been removed.
lib/pleroma/web/mastodon_api/views/status_view.ex: More than 4 attachements
This is an update linked with mastofe!4 (merged) so you can have more than 4 attachements displayed. Also looking at https://github.com/tootsuite/documentation/blob/master/Using-the-API/API.md#attachment it looks like the maximum of 4 is only when posting.