What exactly are we looking at in the video/image? To me, with...

What exactly are we looking at in the video/image? To me, with zero experience in the field, it appears to be a machine that potentially separates smaller particles from larger rock fragments with the small ones falling through holes in the belt and larger ones continuing on to be further refined? In which case the rattling makes sense to me as the rocks are knocked back and forward to separate them.
Also not sure how you gauged that it is even on an angle? That bin with the Bass logo on it appears removed from the imagine. Whose to say that bin wasn't at an angle just sitting there while they took a picture? And when it is finally installed it will all line up? The angle might only be a matter of perspective from any number of things (the screener, the bin, even the angle of the camera taking the video). Or it might be better at an angle like Spec suggested (legit no idea) and it actually is at an angle.
I would hope, and expect, that they have had experts with experience in their fields installing these machines, in which case i'm happy to take their advice that this is how it looks (angle or not). Unless you can provide us with some footage of how you think it should actually look? Happy to be proven ignorant in this case as i really am gauging my belief on trust in the management at Bass.