Dave Bonta's "Elf" is only three short lines, but it packs in a whole mood. The speaker is someone working a seasonal job in a mall, most likely dressed as one of Santa's helpers, though the poem never says so outright. That is an inference from the title. What we get is the plain fact of a long day of work, and the word "all" repeated twice makes it feel endless.
The poem sets two ideas side by side: "my work" and "Christmas day." Christmas is supposed to be a time off, spent with family, but the speaker is stuck in a shopping mall, performing cheerfulness for other people's holiday. The poem doesn't complain loudly. Its flatness is the point. The speaker sounds tired, a little resigned, and maybe slightly isolated. The mood is quietly melancholy, with a hint of irony in the gap between the playful title and the dull, repetitive hours it describes.