Display not working correctly

To add to Reece's answer: You banged or dropped your system which shocked damaged the screen.

Possibly, but not necessarily. On the Airs (more commonly the 13" models) this issue can develop through no cause, it's just a manufacturing fault, usually with the LG panels

The system was dropped yes. There is a small dent on the top right of the screen.

But what doesn't seem to make sense is if there is an issue, shouldn't the LCD not work at all? Why does the screen continue to work if kept in a fixed position on a table?

EDIT: Also updated the macbook Air Linked as it is the 13' model.

The ribbons for the connection from the LCD to the LCD's PCB basically have an intermittent connection; when you are moving it in a certain position this is putting pressure on these ribbons, allowing it to work temporarily.

The screens for that are expensive unfortunately, but it is the only way to resolve the issue :(

@nikhil - Lets think about a similar problem. You have a desk lamp that you knocked off the desk and when you tried using it and was flickering what would you suspect? The light bulb likely was either loose or the filament was damaged.

This is no different here. The LCD glass screens electrical paths to the flexible cable that carries the signal to it got damaged. Sadly this interface is very fragile and not repairable.

Just like the desk light there could be a deeper failure so you tried turning it on and it wouldn't light. While this can happen as well that would be the most extreme failure which is what you are thinking.