I'm making short vertical videos to promote my apps. They are less than 30 seconds long, 1080*1920 and uploaded on YouTube (which recognizes them as YouTube Shorts obviously).
Now, when I set the video in the Play Store listing, I still see it horizontal and not full screen (I tried with the youtu.be and youtube.com/watch version of the link). I want something like Outlook, for example.
How can I obtain the same fullscreen experience? Seems that Google implemented it months ago, but it doesn't trigger for me and other apps, for some reason.
Ok, so the answer is: wait!
After more or less 7 days from the moment I put the video link in my app (the link was a youtu.be link, but I'm not sure it's needed) the vertical and fullscreen preview magically appeared. So well, just wait.