STANDOFF
Aesthetically pleasing effect with depth and shadow
The fact they stick out a bit means the surface of the wall behind the display can be seen from the sides so this must be considered.
The fact they stick out from the wall might mean there is more chance of people 'bumping into it' if it's in a high traffic area
FLAT TO THE WALL (MIRROR FIXING)
This is often called 'mirror fixing'
Aesthetically pleasing effect of the display simply being right against the wall
The fact that it is right against the wall means the surface of the wall behind the display can't be seen from the sides so it can cover up the surface of the wall.
The fact that it is right against the wall means there is less chance of people 'bumping into it' if it's in a high traffic area
