I'm just a few days in myself. If you are curious, keep trying. You'll lose sleep like the rest of us before you know it.
Do you have the energy to track the white through the other photos? That's definitely a thawb - the white drag the saudis wear. And I think they are the only ones who use white for head covering, too. The gutra.
So this anon is being a smart ass, but dang. Dan Brown has his ways. Some of this stuff was definitely in his books. Da Vinci Code comes to mind.
Inferno was population control through a virus like the news that's out with vaccines.