Model of an ambiguous solid.
Look at it from one direction it appears to be a cube, and from the opposite it appears to be a cylinder. Hold it up to a mirror and you see both at the same time.
The 4x model is a group of four of the shapes merged together to produce the illusion of either 4 connected cubes or four overlapping cylinders.
The models ending in correct have been reworked to use a more mathematically correct construction method. They will have a 30 degree up from horizontal viewing angle.
This was very difficult for me to print as removing the supports without damaging the print was a problem.
Take care when removing the support material as it is easy to split the model.
After seeing this video (not my video), I had to try and model this shape.
I created a cube in Blender, subdivided the sides so I would be able to smoothly deform it. I worked from the final viewing angle and distorted the cube until it looked like a cylinder. I switched to the opposite viewing angle and made sure the object looked like a cube.