Two short lines, and they work almost like a single quick glimpse. The poem seems to catch a moment indoors in cold weather, perhaps a crowded place where people have come in from the wet and the smell of damp wool fills the air. Judging by the imagery, the speaker is looking at people bundled in heavy coats and suddenly sees them as bears.
The comparison is funny, but it is also a little odd and unsettling. Bulky overcoats make people look bigger, shaggier and more animal, and the word "disguised" suggests something wild hiding under ordinary clothes. The speaker doesn't say how they feel outright. The tone feels amused and observant, with a hint of wonder at how strange everyday life can look when you really notice it.
The mood is cozy but slightly damp and heavy, like a room full of steaming coats. The smell comes first, and the image follows, so the senses lead us into the joke.