Another note on this ridiculous issue... even if your app is displayed in portrait mode, the app review image has to be landscape. So, I had to rotate my screenshot 90 degrees for the portal to accept it. 1920x1080 instead of 1080x1920.
[edit] Ok, nevermind that. It appeared to take my 1920x1080 image (it showed in the preview box), but when clicking Save, the top of the form said I need to upload a valid preview image, so it didn't actually accept it.
[edit 2] Inexplicably, uploading at 1242x2208 was accepted.
Topic:
App Store Distribution & Marketing
SubTopic:
App Store Connect
Tags: