Can you find the mysterious detail in this picture that's creeping the entire internet?

Family photos are a pretty common occurrence: Many moms and dads want a formal family portrait, so they get together, hire a professional photographer, and take part in a photoshoot.

While it's supposed to be a happy moment with smiles and laughter, one family photo is sending internet surfers over the edge with one creepy detail.

See? It's easy to miss, and we don't blame you. Here's a hint: Look at the left side of the photo...

If you found it, well done! How weird, right?

For those of you who haven't found it yet, notice the little girl's smaller hand.. whose hand is this?

Many people have come up with theories about a ghost hand, according to the website RelayHero.

The first theory is that the hand belongs to a ghost. Whether you believe in the spirit world or not, it's definitely inspired some kind of supernatural belief.

The second theory is a bit more realistic. Some people believe that this is actually the mother's hand, and that the older girl in the middle was added to the photo using editing software.

Look again and decide for yourself..

It's definitely creepy and strange either way. I wonder who this family is and if they can provide answers. Whose hand is this?

Please share so your friends and family can have their say too.