Follow up idea, which I'm sure adds tons more complexity: have each face be a different material or finish. E.g. one face is stainless, another anodized aluminum, zinc plated for a third, brass on another. Each of the edge pieces would have to be a two-part assembly, and the corners composed of the three materials joined together (joinery, screws, brazing).
That surely would feel strange with the varying densities and thermal masses while solving, but would look very cool. To be fair, it appears from the pictures that each center piece's pattern is symmetric, which avoids the difficult part of aligning those when solving (center often doesn't line up when solving a cube with pictures on the faces in place of a solid color).
Probably far too niche for selling these to be profitable, but I'd love to have one.