Im wondering where Reimu went...

My guess? Still asleep

Or lying in wait behind (or inside) the donations box.

Looks more like Moriya shrine to me. Look at the rope, and the mountains are very close too.

There aren't any worshipers: it's probably the Hakurei Shrine.

The Pixiv title says it's the Hakurei Shrine.

MarUsca said:
Looks more like Moriya shrine to me. Look at the rope, and the mountains are very close too.

Technically speaking, every shrine should have a shimenawa over the gates, as it marks the boundary between profane and holy. As for the mountains, the Moriya shrine is on the mountain, as far as I can recall.

This should be the backdrop for when I should enter the Hakurei Shrine in Kamen Rider Decade fashion.