There is a clear setting here—a museum—but it doesn't even matter. Imagine those scenes in romantic movies, where the young lovers' eyes meet across a room, and time stands still: everything else fades away (or even better, if you have experience from real life, you can imagine that, too). That's sort of how we picture this meeting of man and art in this poem. Even if the museum were busy, even if there's a field trip full of children running around, getting in trouble for poking the Van Goghs and sitting on the medieval furniture, it wouldn't matter to the speaker here. There's a real sense of quiet that permeates this whole poem, and we imagine the speaker gazing up at the statue, alone with it in a dark, silent gallery, where it's lit by a single spotlight. The "brilliance from inside" that he describes seems to light the carved torso's elegant lines, as it gleams softly in the darkness. There is a perfect calm, a perfect stillness, as the speaker communes with the ancient work of art, and the timeless spirit of beauty. Now put yourself where the speaker is. Imagine yourself in a space of quiet and reflection. Now you're in this poem.