Three short lines give us a quiet scene: rain falling lightly, and a bear walking through a town. The bear isn't described doing anything dramatic. It simply passes through, and the poem seems to admire that.
The key line is the last one: "needs no advice." People are usually the ones handing out guidance, warnings, and opinions, and the poem suggests the bear has no use for any of it. It knows where it's going, or at least it moves with a calm that doesn't depend on anyone's approval. The title, "Transient," adds to this. The bear is only temporary here, a visitor in a human space, and it doesn't seem troubled by that.
The speaker's feeling is hard to pin down, but it reads as gentle envy mixed with respect. The mood is hushed and unhurried, like watching something wild slip quietly through the ordinary world while the rain softens everything.