If you're looking where Yukari is, she's right next to the tip of the hat.

Should I tag Eirin and Kaguya too?

Top right billboard is Eirin and probably Reisen (Notice the skirt) while Top left looks like Aya Momiji.

Clarifications please?

RaymooHakurei said:
Top right billboard is Eirin and probably Reisen (Notice the skirt) while Top left looks like Aya Momiji.

Clarifications please?

Those are indeed Eirin and Reisen. But they appear too small, I dont think its necessary to tag em. And that black-haired billboard girl does not look like Aya, she got nekomimi. Probably related to the WaCaoNiMa thingy.

Very top of the building the yukari sign is on, you can see the bottom half of kaugya

er, reimu actually

Sleeves looks like Reimu's. But the dress which is patterned blue-red is obviously Eirin's. Background seems to be the bamboo forest, but it is not clear.
In the end, not all that important I suppose.