Half full = Half empty is reality.
Full =/= Empty is also reality.
Two person are having dinner together.
After the first course, person A says, "I am half full."
He stops eating feeling satisfied.
Person B says, "My stomach is half empty". He is eagerly waiting for the next course and feels hungry.
The way they think makes half full not equal to half empty.
Our mind can make things happen. This is because our mind can create qi.
Feng Shui deals with qi. Therefore saying that the use of symbolism is not Feng Shui is not right.