Three short lines, and a whole character appears. The speaker is in a park, watching a raven, and the first thing they notice is the noise. The bird is a "loud beggar," the sort of creature that wants attention and a handout and isn't shy about asking for either.
Then the poem turns. The raven is compared to "the queen of Bohemia," and the begging suddenly looks like performance, even royalty. Bohemia can suggest a free-spirited, unconventional life, so the comparison may hint at a bird that answers to no one and does as it likes. That's an inference, but it fits the playful tone. The last line, "raven at play," settles the matter: this isn't desperation, it's fun.
The speaker seems amused and a little admiring. They don't scold the bird for scavenging. They enjoy its boldness. The mood is light, quick and humorous, like a snapshot of a small, noisy moment in an ordinary park.