We are uploading PNGs with the REST API, and they are working fine on web and Android, but in the iOS app they show up as blank grey squares.
Here is a tweet that is having this issue: https://twitter.com/jenkellyjen/status/650961713177587713
Here are the screenshots of how it looks on web,ios
, and Android. (I can only upload 2 images, but it works on Android.)
Edit: It also works fine on iOS from mobile web.