the situation may be seen in different ways depending on one's point of view and that there may be opportunity in the situation as well as trouble.it depends upon the situation of the liquid in the glass. It's half 'full' if it is to be 'filled'. Half 'empty' if it is to be 'emptied'.But the approach should always be toward positivity , i mean optimistic , one who always believes in the greater good .
In the last paragraph you changed the whole thing by just introducing shallow hole filled with water that was tricky.....it really depends on persons perspective