The walls came down and a larger bathroom (below) was built.
Somehow the only pic for the new toilet.
We only like to use Hardie BackerBoard (same makers of Hardie Lap Siding) - this is substrate for tile. We seal the edges with reddish liquid cement - the drywall has a greenish tint because it's "greenboard" & it's a special mold resistant drywall used for bathrooms.
To the left (shower base) is a rubber membrane that goes up to 6" up and behind the BackerBoard to prevent water leaks.
Our lead, Jose, builds showers from scratch.
There's the reddish liquid cement I mentioned earlier....if you don't see it on your bathroom remodel: demand it.
Above: The finished product
<--To the left, barn doors everywhere