Fascinating to me about this is not just creating a 3-D “bigger on the inside” illusion but also how this is a 2D image which creates two 3D depths in one — and it works simplified to lines.

Fascinating to me about this is not just creating a 3-D “bigger on the inside” illusion but also how this is a 2D image which creates two 3D depths in one — and it works simplified to lines.