That's not entirely true. We found out that three Titmice are visiting the new feeder. This is the first non-Titmouse. My wife thought it might be a Pine Siskin, but it doesn't have stripes on its breast. We tried the Merlin app from the Cornell Labs and it said it is a Goldfinch. Unless it is a juvenile and molting.
This one made itself at home. It got into the box and ate for a while.
It's funny that I said yesterday that I didn't need a telephoto lens with the feeder on the window, but I can't get close to the window or I will scare them away and Titmice are very skittish. Here I used my very long lens, 200-600mm
The wing pattern looks right but the colours look darker than any goldfinches I’ve seen. Even the females in winter usually look like an olive green on the chest but then the colour could be due to the lighting. Hope she comes back again and may give you more clues.