I don’t know why, but I loved his nonchalant, matter-of-fact “I blocked you” at the end. And yeah any normal person’s going to block you for sending that type of stuff. You’re not dating, married, or sex-buddies, so it’s out. It’s a pity. Had she actually sent the picture of the textbook question like she was going to, their relationship could have seriously improved. She could have even started sending “good night/morning” messages and other stuff to get closer to him overtime.