He got it from Denny Borsboom, who says (at his Facebook page), this:
Different scientific models can have equivalent observational consequences. In statistics, this is known as statistical equivalence; in the philosophy of science, underdetermination of theory by data. This is often hard to explain and I know few good illustrations that go beyond Wittgenstein’s duckrabbit. This GIF is a really nice illustration – and beautiful too.
If I knew how to post a GIF here, I would. But I couldn’t make that work.
For me, the the star with seven points is the most remarkable aspect of this.
Wittgenstein’s duckrabbit is presumably that creature that looks like both a duck and a rabbit, depending.