My wife will be going to her biometrics appoointment next week, March 28, and she is wondering, since they will take her picture, if they prefer any sort of clothing? Do they care, for example, what kind of collar she has? She also asked me to see what people here say.

I'm not too sure it is a big deal as to what she wears - They will only be taking a picture of her face. I guess maybe her ears need to be visible.

they make only a pic from her face.. and her fingerprints.. thats it.. nothing special..

It's nothing special, unless you want to meet someone there.

I'd say wear something comfortable because she'll probably do a little waiting.
I don't think they care what kind of clother she has on. Good luck! -Lar

Wear what you usually wear. No big deal...
They will ask to remove any earrings...but that's all

good luck!

They would also ask you to remove your glove if you are wearing one