I'm not sure if the promotion art change is intentional, but the downgrade certainly wasn't.
Good catch! All nonstandard cards do have slightly alternate art for when they're placed as a played card, that is intentional. It should revert back to the standard art when returned to the hand, but it seems I failed to account for this when switching cards via dragging and dropping. I will have this fixed in tomorrow's build!
As for the downgrade to a pair, that is very troubling! I will figure that out as well. I was surprised everything was working so well with the telescope bauble, as I had to write a huge script to get the hands evaluated properly. I'm sure I can find out what's going on.
Thanks for letting me know and video making it clear what is going on.
Edit - this was bugging me so I went and found the problem before bedtime - just some misplaced curly braces! And solved the issue with the non standard cards not reverting back to their original art as well. Thanks again for pointing these out! Uploaded a new build with these fixes just now