Some change the way we see the world around us, but others are more like fun challenges for our brains - and this festive illusion is pretty tricky.
The illusion shows a very Christmassy scene with a fox, a bear and a rabbit all gathered around the fireplace.
There's also a huge Christmas tree with plenty of baubles and presents underneath, as well as a board game, a clock and some other items.
But somewhere hidden in the festive snap there are three bells - can you spot them?
You might have the eyes of a hawk if you can find them all in 15 seconds.
The adorable illustration was shared online by Jargon Josh and it's left viewers totally stumped.
The bells are very carefully hidden in the picture, so look closely to try and find them all.
Need some help?
The bells are spread out across the room, but you can find the first one on the Christmas tree.
If you look carefully, the bell looks just like a bauble, making it especially hard to find.
And the second can be found nestled on top of one of the Christmas stocking hanging above the fireplace.
Finally, the last bell is the hardest to find, but eagle-eyed viewers will have noticed it on the golden photo frame above the fire.
So did you manage to find them all?
