Carpet riddle: where is the phone?

Charlieʼs Drawings' Facebook page posted a photo of a carpet on which the phone lies - in a case with the screen down.

In the comments, users wrote that they looked at the photo for a long time - but only a few managed to find a mobile device.

Unfortunately, the post with the puzzle was removed from the Charlieʼs Drawings page, but the exact same picture was on Imgur. More than 8,000 people have shared the post on Facebook since its publication.

If you didn't find a mobile device in the image, then here is the answer.