Why do you seem to have it in for jumpers on dogs who feel the cold?
I thought from the thread title you were objecting to reindeer antlers and tutus on dogs, which I think you'd sort of have a point about, if it wasn't for the fact that most are put on for 5 minutes to take a photo then never seen again.
I had labradors, I loved the look of dogs in outdoor proper doggy coats, but mine never needed them. I bought one for my ancient arthritic girl, thinking she'd appreciate it in winter, but she was much happier without it so she never wore it.
I have a totally opposite stupidly nesh cross breed rescue now who shivers violently when she's too cold - so of course I'm going to put a coat on her when we go out for our walks in winter. She never seemed to have strong opinions about her coat either way for the first two years but this year if I offer it to her she will actively poke her head in and help put it on. I never thought I'd be the type to have a dog who needed a jumper in a centrally heated house either, but again, she's made it very obvious that she is cold this winter and is a demanding pain in the ass little madam fractious in the evenings until I put a jumper on her and she settles down happily.
Same dog manages to accidentally pull her legs out of, or step out of the neck hole of jumpers that don't fit her well because she's an awkward shape. If that happens and I take the jumper properly off its about 50/50 if she will settle quite happily without it or will clamber over me, poke me with a cold nose or paw, and eventually start yapping at me until I hold the jumper open for her and she pokes her head through again to put it back on.
And yes, shock horror, she has a Christmas jumper! 
Dogs are individuals. You have no idea why any specific dog is wearing a jumper, whether it's festive or not. Even if it's for fancy dress, it's not the biggest crime in the world for a couple of weeks in December, and please credit most dog owners with just about enough nauss to recognise when their dog is too hot or is distressed by their clothing and to do something about it.