YouTube video playback at Galaxy Store (watch faces) is always in landscape format 16:9 ratio, while it also supports portrait 9:16 format. But Galaxy Store automatically flips portrait format to landscape ratio, even at full screen mode. That reduces the viewable area dramatically.
Themes Store playbacks portrait video format without forcing it into landscape ratio. This is the correct ways to playback portrait video.
Portrait format is the optimum ratio to demoing watch faces and themes. Plus, every Galaxy Store layout is in portrait format and users are browsing the store in portrait format. From UX point of view, users would have a better experience when everything is in portrait format.
Related Menu or Feature:
YouTube video in Galaxy Store listing.
Detail description of the Feature Request:
Support playback portrait Youtube format video in portrait format, just like how it is at Themes Store.
Better Galaxy Store UX experience for users.