You might look at a bruise as something to cover up. Hide it until you recover. One Twitter user saw something else: A Pocket Monster.
Here, Pokémon Gastly, a black ball of glowing matter surrounded by purple gas, takes the place of an unsightly black-and-blue spot.
The text bubble reads, "Ah! A wild Gastly appeared!", while it says "Gastly Level 22" in the upper left.
To see a full-sized version in the gallery, click on the lower corner to expand the image.