I didn't think it was too many.You always post too many pictures. It's hard to pick any single image to respond to.
Mosaics are not an officially recognized breed, but there are a group of breeders working towards that goal. They shouldn't be bred any which way and still use the name.
Mosaics must have blue ears. But blue ears don't make a Mosaic (Silkies, etc.).
The feathers should be patterned with white - the exact look is still in flux.
They have green legs. Blue skin. Blue beaks. Small straight combs.
Fibro is interesting to work with. I have some homebred fibro eggers that came out dark as night everywhere from Mosaic x Black Ams. Kinda cool. Also lots of sheen, reinforcing the idea that ACs were used heavily in Mosaics.
I would hazard a guess that the question askers hen is AC x Leghorn, based on the heterozygous dominant white, and the strong fibro expression.
Mosaics are still new to me, still learning. Any information is appreciated.