I don't get how you ID these. This looks exactly like the ruby-crowned kinglet to me.
ETA: I also have other pics I don't post which help in IDing.
I use the Merlin App to identify the birds we see and don't know ourselves. That said, there are many differences between this and the tiny Kinglets.
These confusing fall birds are harder for me because the Merlin App has a tougher time nailing it down to one species, and the pictures they show don't look 100% the same.
Here is a short article I found useful, which helps show some different things to look for when IDing birds.
https://www.audubon.org/news/how-recognize-six-warblers-their-fall-feathers