His notice instant is— (4)
Notice how stating the surprise in a “normal” way doesn’t compare to the moments of surprise that contain poetic imagery. The question is, who notices who?
Have passed I thought a Whip Lash (13)
“[T]hought” sets you up for the amazing transformation of the snake. The snake first exists in the speaker's mind (mistakenly) as a whip, but then "transforms" into the reality of a snake. The reflection seems tinged with amazement in this moment, as the previously-assumed reality in the mind twists into a new, snake-y reality for the speaker.
Several of Nature’s People (17)
Where is the line between expected and unexpected, between ho-hum and amazed? The speaker seems to dance all over it in this poem, just as he dances along the distinction between humans and animals.