The media entities for animated GIF describe a static thumbnail. The idea behind this is that a media entity can always be used as a photo media entity, so that old clients that expect all media entities to be of type photo will still be able to render them. Developers should never edit URLs or assume a certain URL format is guaranteed.
The indices of the extended media entity are indeed incorrect
sorry about that!
The aspect ratio is reduced. We currently wonât be returning the actual dimensions of the .MP4 file, but this may change in the future.