Cheating is the fun part of Set Designing. There are many reasons we need to cheat a set. It is a common necessity when recreating a location set on the stage. Cheating is problem solving. It is creative solutions. It is tricking the eye; the object is to do so undetected by the viewer.
We use forced perspective to make a set look longer than it is, because the studio space is too small, or the build would be too expensive.
We cheat heights all the time. A fire escape outside the location window. We shoot the POV out of the window on location, then re-create the fire escape on the stage, to shoot the POV inside the window.
The upstairs of a set is usually on a 4' platform, so that we can build the last few steps as if to suggest to the viewer that the whole staircase was there. In fact, the handrail is dying into the studio floor. The downstairs set has a staircase, but there's an actor's access stair at the top of it.
Window sills are often cheated. On location they may be at 25" from the ground. On stage, we would need to raise it to 36" in order to avoid shooting the studio floor outside the window.
We cheat window reflections by gimballing the windows and mirrors. Sometimes you can really tell; gimballing can be tricky, depending on the depth of the gimbal and the exposure of the jambs.
The best cheaters rise to the top. A good cheat always saves the day.