What indeed is here is there; what is there is here likewise. He who sees as though there is difference here, goes from death to death.(Katha Up. II.i.10, 11)
This is to attained through the mind. There is no diversity whatsoever. He who sees as though there is difference here goes from death to death.
This is similar in intent to the Tantric: 'What is here is there, what is not here is not anywhere'. The idea being proposed is that the object which appears is a limiting adjunct of the absolute. Appearance is their reality. Looking for greater ontological depth on the plane of appearance in a quasi Kantian noumenon, in the appearance itself so to speak, is a mistake. In a failing light my car appears to be grey but it is in fact blue. There is a real thing that appears to have a certain quality. 'Appearance' as used in Advaita is analogical. Advaitic appearance is not tied to the reality of an object that appears but to the creative power of the absolute.
To further the difficulty, ordinary everyday appearance is used in the snake/rope confusion story to explain the nature of superimposition/adhyasa.