Here is an example of a spring hokku you will find attributed online to Buson that demonstrates all that a hokku — in my view — should not be:
It spits out cherry blossoms;
That is the kind of cleverness that destroys good hokku. It is written entirely from the imagination — just a surreal fantasy. The mountain is not treated as a mountain, but is personified as something that swallows and spits.
You may also find the verse in reverse form on the Internet, like this:
Swallowing cherry blossoms,
It spits out clouds;
Which is original? It really does not matter, because either way is still bad as hokku.
The point of course, is that the white of clouds above Mount Yoshino are likened to the white cherry blossoms blooming on the mountain. But the way it is done — the mountain sucking in one and spitting out the other — turns it into a vulgar joke.
The better treatment of two similar subjects is demonstrated by Kyoroku in this summer hokku, which in English we can classify as a daoku — a verse without the thinking, imagination, or commentary of the writer added:
Above white cloth
Spread out in the sun —
That way we have the direct sensory experience of the white cloth and the white clouds as they are — and not smeared with the imagination of the writer. And we feel the breeze in the billowing of the sheets.
If we were to write a similar verse in English, it could be something like this as a summer daoku (but we are not in summer yet):
Above white sheets
Billowing on the clothesline —
I think many young people today do not know that something has been lost in the transition from the old outdoors clothesline to the indoor dryer.