Family pictures are commonplace: many moms and dads want to have official portraits of their families, so they get together, hire a professional photographer, and pose for the camera!

While this normally a very happy time, what with all the smiles often seen, one family picture is sending internet users over the edge with one creepy detail.

Do you see it? It’s quite easy to miss, so we don’t blame you. Here’s a hint: check out the left side of the photo…

If you’ve found it, good for you! How weird is that?

For those of you who haven’t found it, check out the smaller child’s arm… Whose hand is resting on it?

Many people have come up with theories about the phantom arm, according to RelayHero.