Created in PrusaSlicer with modifier meshes, read this tutorial to learn more:
https://blog.prusaprinters.org/model-with-prusaslicer-modifier-meshes-tutorial

If you slice this yourself, make sure that the infill anchoring is set to 0.
I've updated both the G-code and the 3MF to have this already set-up. This way, all 4 sides will look the same and pretty.

The old version had 2 nice sides and two that didn't look quite as well.

I've also changed the 3MF and use a height-range modifier instead of a modifier mesh. The result is the same, but it makes more sense this way and is easier to modify.

Printed from Prusament Mystic Brown and Prusament PLA Oh My Gold.

I think it could also look really nice with a color change right where the visible infill begins, if you try to print it that way, I would love to see a picture of it :)