How come Dain doesnt know Paimon when we first met him ?

So Pierro brought Paimon to King Irmin and let her stayed in the palace for a while and Dain doesnt notice that there is a small white fairy flying around to play and finding something to eat ?

What about the Sinners then ? Could they also know Paimon when Pierro showed her to Irmin ?

Hroptatyr probably didnt care but Vedrfolnir probably thought something is going on but either didnt care or didnt have a chance to investigate further.