so. a lost media type search!!! or maybe partially found. i don't know what this classifies as by any means. (CLICK "KEEP READING" FOR MORE INFORMATION!!!!)
me and @zachattack493 (another member of this blog) have a theory about the Let it Snow (the in episode video, soundtrack version of the song and the credits scene)
"There is a theory we’ve concocted that there might be a secret hidden full music video for “Let it Snow” sung by Isabella judging by some of the footage seen in the show, where some of the lip movements look like there’s going to be another word sung just before or after the scene changes." -short explanation by Zach
(HQ/creditless video of this footage thanks to Cath on YouTube!!)
here's the credits scene in question to (kinda) show you what i mean. though i'm not sure exactly how to explain this in text, watch the last few seconds of the video (when the ski lift scene starts).
though it could just be an animation error of some kind and this entire thing could just be speculation, i do not see her mouth making an 'O' shape in that last few seconds (when she comes out of the snow mound and enters a skating rink, just before it cuts to the Disney TVA logo). there's also a fadeout between that and the ski scene before it so i wonder if that could be another...evidence piece?
i know this isn't exactly a 'professional' sounding explanation it's the best i can give for this. especially since the show's video for the song was cut due to time and the full version (which was released over a YEAR before the episode the visuals for it appeared in came out at all - episode in question is a Phineas and Ferb Family Christmas) is around 2 minutes and 10 seconds long while the show's version is a minute shorter.
ON TOP OF ALL THIS, i asked Charter School Girl about this on one of their recent videos! no idea if anything will come out of that though but i figured it could work because Charter School Girl has uploaded previously unseen P&F content, so maybe it could work! my comment to them is below:
don't know what else to say about this but here's to hoping this goes well! if anyone wants to help with this in some way please join the Discord Server linked in this blog's pinned post :)