I don't really know what's going on here, is he smelling his hair..? Eating it...? W-why, nishikuji?
I'm a year late but I wanted to say what's going on is that Argalia has the same long white hair as Angelica, and they do look alike or even identical if you covered his eyes, so Roland is pretending Argalia is Angelica here and thinking about her while burying himself in "Angelica's" hair. Argalia is laughing cuz this behavior is pathetic and desperate. Pretty fucked up but cool work. At least, that's my analysis of it.
