Can someone scan your eye through a picture?
Discussion
These days, yes.
And more importantly, your fingerprints.
Which is why I don't post my face or my hands on anything public.
Do you use fingerprint or faceunlock on your phone?
Pfft. No.
Even if I did, it's not phoning home to Google, so...
Also, at least in the US biometric data is not protected. Passwords still are. After I learned that, I stopped using fingerprint readers and have never used facial unlocking.