"Sunshine" is a short, quiet poem about someone who was once known for being cheerful and has lost that brightness. The opening line, "They used to call me," breaks off before it names anything, though the title suggests the nickname was Sunshine. That unfinished sentence makes the speaker's old identity feel like something already slipping away.
The speaker remembers being "so happy and never sad," with laughter all around. Then comes the turn: the laughs become "toxic like the tears." The comparison suggests that the joy around the speaker has soured, or that the speaker no longer trusts it. The final lines return to a bright morning and flowers in bloom, but the beauty feels distant. The speaker ends by wondering how it is "for a person like you," which could mean someone still able to enjoy this. The mood is wistful, lonely, and a little hollow, with the ellipsis leaving the thought hanging.