Even turtles can nosebleed.

When and where matter not; Mugi sees all yuri.

Didn't notice Mugi, despite tag.

That's one of the best artistic uses of a background detail I have even seen.

Can't see Ui... where is she?

Like the stuff on the labels, "Listen!!", "HTT"(Assuming that isn't some normal thing on labels.), and is the "Working!!" label reference to the anime?

Whoa, you're not kidding. Those labels are full of Easter eggs. The one to the far right reads "Azu-nyan", for instance. And the "WORKING!!" symbol would be debatable, but that knife-and-fork logo makes it pretty clear.