It's just the artist being lazy. I don't think the novel specifically pointed out he wears the same style clothes everyday... kmhoshik
At least not in this arc yet. In other arcs, the way he dressed himself were written in details (cause it's from Lee Yeon's POV). Well I guess we just have to make do with that underwhelming shirt and jeans... For now. Lol. He will change soon I think when he gets a job
I'm going to cut a cake when the artist changes his clothes...