I think, considering that the custom overlays are apparently handled case by case(????), this would be a wonderful addition to the site for those extremely invested in their pets and their stories.

There's a code for it

<style> { -webkit-transform: scaleX(-1); transform: scaleX(-1); filter: FlipH; -ms-filter: "FlipH"; } </style>

OH dude yes! I think this would be amazing, I would definitely vote for this x'D

If possible I think this would be cool, but I understand if it would be simpler (if disappointing) to just have it be an overlay thing one can do on their own. Either way I think having pets face each other could be cute!! I would worry if there are any on-Subeta things it could mess up, but I can't think of any- on another petsite there are places where it matters what direction a pet is facing if they get hit with an in-game trap or other damage, for example. I'm no battler so I'm not sure if it could become an issue in a battle here... but if that were the case having it be a (semi)permanent overlay would mess things up in some cases when otherwise a coded "direction" for how the pet was facing would work better to avoid having a pet get "hit" from behind, et cetera. But that may just be a given issue we have to deal with for the moment- and I may be overthinking this, oops.

Edit: not to mention asymmetry might be an issue for people with more complicated overlays. One might not want to have to draw a whole new version of the art to show the other side, if that even somehow got coded for, and if staff somehow felt they had to draw both sides of every pet color combo.... it would be a pretty big workload, if users expect the symmetry or would get upset without it and staff felt they had to. So you might be going from one kind of complaint to another here.