why don't you get a full, beveled mirror to fit the space and have them cut holes in it for the sconces? that would look best

(i realize this is much bigger, but it gives you an idea)

Beautiful herringbone tile!!! Look for something round or oval to break up the rectangle shapes. What finish is your faucet and scones? Who uses this bathroom? Are they tall or on the shorter side? Just some things to consider when selecting a mirror. Overstock.com is a good source to get some ideas as is photos on Houzz!! Pottery Barn also has a nice selection (can be a little expensive).

We specify this mirror from School House Electric for bathrooms. Perfect Scale :) Looks like it might work in your space too. https://www.schoolhouseelectric.com/collections/mirrors/products/higgins-mirror

Thanks everyone!

Something tall and narrow framed to match your faucet. The beautiful tile should not be hidden.

oh shoot, good point felizlady! totally forgot about hiding the tile.

maria, something narrow at the top and wider and the bottom then.

Maybe try an oval mirror with the sconces? Two bathroom designs of ours are included here to help.

Awesome input everyone! Thank you