The only problem is, he isn't really wearing a poppy. Instead, someone's crudely photoshopped one onto a photo of Cameron that dates back to 2010. Here's the original.
Here's a before and after.
People were quick to call out the attempt to stick the mark of remembrance on the prime minister's portrait.
While other people had a few criticisms of how the photoshopping was done.
Cue panic in Downing Street. Within an hour someone had managed to find a real picture of the prime minister with a poppy and update the Facebook profile pic.