Lan Wangji doesn't necessarily understand joking or sarcasm but he has been trying to better realize when someone is attempting to make a joke. But what is more important is that this man seems like one of the leaders of their group and so of course he will respect that. He is fine and willing to pull his weight with whatever is needed of him.

"I can move debris if needed. Some things will work well as means to block further blockages from occurring."