Yes, that behaviour is not normal

Frowning, Jason put down his trowel and picked his way carefully out of the garden beds towards the young man, taking care not to step on any of the plants he'd been tending to.
"Sorry, I don't mean to, look I'm just sketching and I nearly had you finished? Are you done? Would you mind going back so I can finish the sketch? It's for a good cause I swear."
Jason paused as the guy brushed the errant lock of hair from his forehead again and looked up at him earnestly. "What's the good cause?"
"Um... me making it through Art this semester?" the man said. "I have a folio due and I didn't really find anything inspiring until..." he blushed suddenly and dropped his gaze.
"You find me inspiring?"
"Well, not just you...per se..." the man said. "It's the way you move, the way you focus when you work and the fact that your hat isn't the same boring green as everyone else's. You're different and I kind of wanted to sketch that."