Jessie J and Pauley Perrette: Identical?

One is known for the hit single Price Tags, the other for her role in the TV series NCIS.

So, which is which? I hope I’m not the only one thinking that these two lovely are more or less identical. They both have black hair, a straight fringe and everything. Though they don’t have the same facial structure, but at certain viewpoints they do look like the same person. I, myself, have mixed them up a couple of times, especially since I had no idea that Pauley (the one on the left) was in the music business as well.