Stare at the image and see if you can work out the triangle.
The cubes have been projected as 3D objects very effectively here and colour has been used to trick us into seeing the triangle change shape and twist around on itself. Does it make sense?
If you begin with the purple square and follow it down to the green and then the white (cover the black squares), it does behave like a triangle and the perspective is correct. It is only when you look at the black line of squares that the shape falters and the perspective changes.
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