I'm guessing Yukari has visited by gapping from boxes so many times that Yuyuko is no longer surprised?
Nwha!?PoinkYou have to throw them away properly!You're right.You Have to!PoinkWhat shall we do, Yuyuko-sama?!Good question...Ker-fumeYoo-hoo!Yoo-hoo!Bfmp!Oh, my.Streeeeam