If I’m not mistaken there’s no “front wall” to your room. It looks like the sun is pointed down and to the left.
The top shadow would be from the ceiling, and the one on the right from the wall on the right. Sun lights are a little tricky as it doesn’t really matter where they’re placed,
The red is mostly bouncing off of the column, I believe. Also, if the surface has roughness and or diffuse to it, some of that is going to bounce up. Think of rough paint instead of glossy. Some of the geometry is going to bounce light up instead of acting like a mirror and “perfectly” redirecting light.
Sun lights can be a little tricky. It doesn’t matter where they’re placed, only the direction they’re shining. Try rotating along the Z access to the right – clockwise. You should get to a point where the shadows are coming from the wall on the left instead of the wall on the right. You could also rotate up and down and have shadows coming off of the floor, if you wanted.
