Two short stanzas set two worlds side by side. In the first, the speaker wakes on a train and sees a hawk. We don't get where it is or what it's doing, just the bare fact of it, which makes the moment feel sudden and clear, the way things do when you've only just opened your eyes. In the second, the scene shifts to the people nearby: men laughing about office business.
The word that tilts the poem is "absurd." The speaker doesn't say the men are cruel or boring, only that they seem ridiculous next to what has just been seen. The hawk is wild and silent and belongs to the landscape outside the window. The men carry their workday with them into the carriage, even in transit.
The mood is quietly wry. There's a touch of amusement, maybe a little detachment or gentle annoyance, and a sense that the speaker is still half in the hawk's world and not yet ready to rejoin the human one.