The poem is built on a simple repeated pattern: you see someone, and you wonder. A girl with cuts on her wrist, a boy with tired, shadowed eyes, and finally the speaker, covered in bruises. Each person carries visible signs of hurt, and each time the "you" in the poem only wonders. Nobody asks, and nobody helps.
The speaker's tone is quiet and worn down rather than angry. The phrase "you just can't help but wonder" sounds almost sarcastic, as if curiosity is the only thing people can offer. Wondering costs nothing, while reaching out takes effort. That gap is what the final lines hit on. The speaker sees "humans" but not "humanity," meaning plenty of people are around, but the kindness and care that should come with being human are missing.
The mood is lonely and heavy. The short, plain lines and the lack of any answer leave the poem feeling bare, like someone saying something painful because no one has bothered to ask.