The vertical accent tile is outside of the glass line. The glass falls halfway on the quartz sill and the accent tile is aligned with the front edge of the sill.

How wide is the accent tile around shower?

I would estimate the band of tile down each side of the shower, and the horizontal band under the window are each 3" wide. The band running horizontal through the shower is approx. 5" wide.

Is the shower seat pitched? If so how? I have same situation in my bathroom where decking flows into the shower seat. Don't know how to pitch seat and have granite remain appearing as one piece.

In this case it is not sloped at all, but it completely flat. The client knows this and uses a squeegee after shower use to clear any standing water. The only alternative would be to have a seam in the quartz directly under the glass and slope the seat portion.