Achoo! Sorry, my hayfever's been playing up again. Let me just grab a tissue from my Steam Machine... is something you could be saying if you're willing to 3D print the replica this generous individual over on Reddit designed and shared.
The Steam Machine Style Tissue Box Cover (or 'Enclosure') is, practically speaking, just a tissue box. But I'll be damned if I'm not tempted to buy a 3D printer just to make one. It looks very much like a real Steam Machine, sans all the actual gubbins that makes it, well, the real thing.