You don't need to do window reveals 1st , just cut the tiles to the required thickness around the window then slip the trims in.
Just as easy as doing it in pic 1 as it is in pic 2 IMO 🙂
Well,just normal Charlie ,as I would doing it pic 1 way, have a do ,when I first saw it I was a bit confused ,but it's actually a piece of wee wee ,just as if not easier that pic 1