Contrast on the bricks is too low compared to the planks. At first I thought it was some sort of carpet, that's how low it was.
Hue-shifting on the bricks seems to go from warm to cold as it gets darker, although the whole thing consists of cold, muted colors (grayish pink and gray to grayish purple) as a whole. Likewise, on the planks it gets warmer as it gets darker, while the tiles are comparably warm and contrasting (orange-brown to dark orange-brown to black) and even have a border/black outline, a thing that should be either gotten rid of, or added to the brick wall.
This makes the tiles seem to clash color-wise. Judging by tiles on the top, these two tiles will be layered on top each other and the clash becomes immediately even more apparent.
Other than that the bricks on the brick wall lack any sort of shading or definition. After a closer look they seem to be simply outlined. Pegs supporting the dock also seem to lack a shadow cast by the dock above them.
Excuse me for tossing around so much terminology, I tend to do that. Especially today.