This look was popular in the 1990s and early 2000s to add visual interest, and usually featured a small strip of tile in a contrasting shape and color wrapped around the inside of a shower stall.
Think of it as a water-resistant walk-in closet of sorts with stone or tile floors and walls, a drain in the floor, an open shower ... expensive than a single-stall shower or an old-timey niche ...
The term wet room generally refers to a room-within-a-room in a primary (or large) bathroom. Think a water-resistant walk-in closet of sorts with stone or tile floors and walls, a drain in the floor, ...