And you're used to the weight of the glass, which you instantly recognize when you pick it up. If it was a different weight than you were expecting, you'd probably slow down and be more deliberate.
If you were to just do the exact same robotic "throw" action with a glass of unexpected weight you'd maybe not throw hard enough and miss, or throw too hard and possibly break it.
If you were to just do the exact same robotic "throw" action with a glass of unexpected weight you'd maybe not throw hard enough and miss, or throw too hard and possibly break it.