Pierre - the face on the wall does not add anything so to me it is a distraction. What is visually important - is the row of blue rectangles on the wall and the guy in blue jacket slots nicely into this pattern. But he needs to be positioned between two rectangles, not merge with one. It is good to take a step back and think, but from what I learn more often it is important to make two or three steps forward and close up on your model, it is definitely the case here. By doing so you will ,take a more intimate portrait of the guy, and in the process you will eliminate the much distracting ground and the line between the ground and the wall. Had the guy stood much closer to the wall between these blue spaces in his blue jacket and became a part of the pattern, he would look like belonging to this environment. Otherwise he is just that - a stranger. When you shoot someone with this kind of background its better either to put him closer to the wall and use wide lense with a close up for a dramatic effect, or put him like 20 feet off the wall and use 200 tele with 5.6 f to create a colourful blurred background.