Just the entrance of one new face perks Dagur right up. There aren't many new people in Winterhold, and most who visit are there for the College, and don't need his drinks and beds.
So he tries to be particularly attentive to the Dark Elf seated at one table, with a pile of documents in front of her. There's even a temptation to hover, as if a glance away for a moment will cause any new business to disappear.
Especially with the snow billowing outside, and Nelacar giving half-concealed glares to anyone nearby.