The speaker admits to something unexpected: a spiritual feeling about liver, the kind of organ meat most people treat as plain food or avoid altogether. The poem is only four lines long, and it works by turning that ordinary thing into something strange and almost holy.
The images come quickly. The liver is a "lone wing," which makes a heavy, dark organ sound light and a little bird-like. Then it becomes "a dark home," a place of shelter that is also closed and shadowy. The last line, "settling accounts with someone below," is the oddest. It suggests judgment or payback, as if the liver were a kind of ledger or court. Judging by the imagery, the speaker may be thinking of the body as a place where debts are quietly kept.
The mood is hushed, curious, and slightly eerie. The speaker sounds serious but also a bit amused, finding awe where few people would look.