Sarah's poem is about missing someone and wanting their approval so badly that the mind invents a scene to supply it. The speaker imagines resting their head on a chest while someone plays with their hair, and the warmth of that moment spreads through the body. In that daydream, they repeat "he'd be proud of me," as if saying it enough could make it true.
Then the illusion breaks. The speaker realizes their head is only resting on a desk, and the tenderness was never there. The poem doesn't say who "he" is, and the odd phrase "my our chest" hints that the speaker's own body and the other person's blend together in the fantasy. Judging by the tone, the person may be gone or out of reach, though the poem never says so.
The mood is quiet, tender and a little aching. The repeated line at the end sounds different from the first time: no longer soothing, but lonely, like a hope the speaker holds onto without anyone to confirm it.