Maybe you would have a "small psychological block" in your head about tucking a bottle of juice in a pocket of a backpack carrying a bomb.
But then you would also be likely to have a "large psychological block" against strapping a bomb-laden backpack onto your back, in the first place.
A cold-blooded jihadist who is capable of that, is also capable of sticking an innocent-looking bottle of juice in his backpack - the better to deceive the infidels.
If these guys are jihadis, they might be dead, i.e. suicidal, and currently spending time with 47 virgins, although being vaporized might make it difficult.
You’re right that jihadists would be told to make the bomb bag look as innocent as possible, but - in this case - I think we’re barking up the wrong tree.
The two guys in black jackets and khaki pants - now they look a bit more suspicious. Those earphones make me wonder... in one ear like they are listening to a police scanner...