Usually, when we connect a laptop to a projector, the resolution of the laptop changes so as to adjust with the resolution of the projector.
That's why the application looks different.
If you notice (and I think this is the case here) the objects do not actually move randomly, they zoom in comparing to the background image, so they move out of the visible borders of your application.
One way of dealing with it is to try to keep always the same aspect ratio in the the resolution. Also whether you use Normal or Smaller fonts in your Windows settings might be relevant.
For example, two machines with the same resolution, the application will look totally different if one machine uses Smaller fonts and the other Normal fonts.