Threads.net attachments missing preview

File attachments via accounts from Threads.net are showing URLs that feature parameters after the filename (i.e. image.jpg?xyz=123) from https://scontent.cdninstagram.com/

This is an issue in at least Pleroma-FE and Soapbox-FE from my testing.

• Pleroma-FE: https://mikuobsession.net/users/$Ap5brqQV95O3PbmYGe
• Soapbox: https://fgc.network/@wario64@threads.net

Clicking into the image reveals the file correctly but nothing is produced for the thumbnail. I'm unsure which of these two articles would help me do something about it for my instance:

• https://docs.pleroma.social/backend/configuration/howto_mediaproxy/
• https://docs.pleroma.social/backend/configuration/storing_remote_media/

Any suggestions would be helpful. I'm unsure if this qualifies as a backend bug yet, so I'm posting up here first.

This is because Threads.net doesn't include attachment mimetypes in the objects. I use this workaround, not sure this should land in upstream

diff --git a/lib/pleroma/web/mastodon_api/views/status_view.ex b/lib/pleroma/web/mastodon_api/views/status_view.ex
index 3ec5d8238..a91f62d6e 100644
--- a/lib/pleroma/web/mastodon_api/views/status_view.ex
+++ b/lib/pleroma/web/mastodon_api/views/status_view.ex
@@ -604,6 +604,7 @@ defmodule Pleroma.Web.MastodonAPI.StatusView do
 
   def render("attachment.json", %{attachment: attachment}) do
     [attachment_url | _] = attachment["url"]
+    attachment_type = attachment["type"]
     media_type = attachment_url["mediaType"] || attachment_url["mimeType"] || "image"
     href_remote = attachment_url["href"]
     href = href_remote |> MediaProxy.url()
@@ -615,6 +616,7 @@ defmodule Pleroma.Web.MastodonAPI.StatusView do
         String.contains?(media_type, "image") -> "image"
         String.contains?(media_type, "video") -> "video"
         String.contains?(media_type, "audio") -> "audio"
+        attachment_type in ~w[Audio Image Video] -> attachment_type |> String.downcase()
         true -> "unknown"
       end