What a fun bird, they are hard to capture. Is that a bird feeder that has the mirror on the outside so you can sit right up to it and see them without them seeing you? If not, I wonder how well those work. I have seen them in the stores and always thought they would be something fun.
No mirror, Jen,
it is just attached (2 suction cups) right to the window. I am about 12 inches away. Here is a shot I have made no attempt to do anything with - I post it because it shows "attachment to window"
Chickadees and Nuthatches are both so tame they ignore me on the other side of the window. When you first put one up they will probably shy away from movement on the other side of the glass. By day-2 they know it's nothing to worry about.
Rusty