The title sounds like a label on food, and the poem plays with that. "Expiration date" suggests something past its use, something you'd normally throw out. But the speaker takes the opposite view: if it is dead, it belongs to us. The word "ours" makes this feel shared and tender, almost like a claim of care.
The poem then lists what we might do with the dead thing. We could "put on ice / till night," which reads like a practical, even slightly dark, bit of storage, as if grief can be postponed until there's time for it. Or we could simply "sit with" it and "get / to be at ease." The poem doesn't say what "it" is, so it could be an animal, a person, a memory, or a loss in general.
The mood is quiet and calm, with a faint edge of dark humor. The speaker doesn't flinch from death. The poem suggests that accepting it, sitting beside it, is how comfort slowly arrives.