Dbrand made a Companion Cube skin for Valve’s new console. Valve owns the copyright for the Companion Cube, since it is from one of the games they made. Valve sent a cease & desist to dbrand, for infringing on their copyright. Valve could absolutely make a Companion Cube skin of their own, if they wanted to.

Dbrand wasn’t doing anything notable with their skin, except that they were the first ones to announce it. But it is a clear violation of Valve’s copyright, and Dbrand didn’t even bother checking with Valve ahead of time to form a partnership contract. If Dbrand wanted to do things properly, that would have been step 0. But they just skipped it entirely, and started selling directly to customers. So naturally, Valve slapped them.