That's this year's permutation of lights-in-the-shape-of-a-tree. It's nine feet wide and 4 inches deep, but it can be seen from the road (if the curtain's open), from the front door and from three rooms.
Last year's, and some before that, and another artsy not-a-tree are here:
Trees without a tree
Lights and Invisible Tree
Christmas Meme, Mimi (shut your mouth, it's Christmas)