This is a Christmas-themed fidget toy. The two trees sit at the top after assembly, which is somewhat finicky, as the whole articulating assembly must be held in place before a 3D-printed dowel is stuck in, securing it in place. You can rotate the trees at an angle, and they rock back and forth via a 4-bar linkage. The four bar linkage lets them slide (I apologize for not having an assembled picture I ended up snapping one of the small pins by shoving it in with too much force it is totally possible to assemble just take your time).