They text about nothing; Draco complains about her homework, demands daily cat pictures, teases and makes clever jokes that make Harry laugh at his screen. He texts her back about all the naughty things Hedwig does, tells her about the songs he likes to play, and takes the bait when she lays it out. Harry likes it, having her in his pocket like this. He finds out that she studies philosophy, but takes extra courses in German literature, because apparently it’s just that interesting.