It's been a while since I did this myself, so I'm speaking from memeory and not truly recent experience... Videos uploaded to Photoshop.com through Elements' Backup and Sync mechanism are re-encoded on the server for web playback, and the maximum resolution for this is 1280x720. So if you sync 1080P video to Photoshop.com using Elements, it will be scaled down to 720P. If your video is 1280x720 or smaller, the native resolution of the video will be respected. If you also use Premiere Elements, and want higher res video, I recommend you sync videos to Photoshop.com vs using Premiere Elements' publishing mechanism, which scaled HD video down to SD (480P I think), last time I used the feature. The Elements team might have updated the publish settings for Photoshop.com, so I'm not 100% sure my memory represents the current experience. I recommend you try syncing an Elements album with just one video to Photoshop.com, and see what the results look like.
