When dealing with the ‘photos’ in ATV, here is how it works on mine: When I move the cursor to the photo row, I can then also move side-to-side to select/highlight the different photos. There could be up to 5 of them, but it seems Zwift will only allow me to upload 3. Under each photo is a green ‘Selected’ (or something like that) or a red ‘Ignored’. (If 3 or fewer all will be selected for upload.) If I DON’T want the photo to upload I click the remote touchpad once. ‘Selected’ then changes to ‘Ignored’ and the photo won’t upload. (I think you may still end up with some sort of ‘generic’ Zwift photo in your Strava feed, though.)
To add to this, once you have a photo highlighted, if you swipe up again it should highlight the green ‘graph’ in the upper right of the photo. Pressing the touchpad while this is highlighted will then toggle back and forth between the ‘standard’ and ‘clean’ versions of the photo. And while you have the photo highlighted (just the photo, not the graph), if you double-click on the touchpad it will highlight the ‘star’ in the upper left of the photo and this will become the ‘cover’ photo for your activity in the Zwift feed. This selection doesn’t seem to translate to Strava.
I hope that helps a bit. If you’re still having issues please let us know.