These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Genius Bonus: The poem Daffy 'recites' after falling with the anvil is the first stanza of Longfellow's "The Village Blacksmith".
Daffy: Under the spreading chestnut tree, the village smithy stands / (The anvil gets erased and replaced with a large artillery shell) The smith, a mighty man is he with large and sinewy (Shell blows up)hAaAnDs...
Fridge Brilliance: It fits because he is pounding on an anvil (that, in the previous gag, was a parachute that he deployed after jumping out of a plane; it goes about five seconds before it's replaced with the anvil and sends Daffy rocketing towards the ground).
It Was His Sled: Is there anyone left who doesn't know that the animator turns out to be Bugs?
Unfortunately, audiences in 1953 probably knew it was Bugs right from the start, as the lobby card (cartoon shorts' equivalent to movie posters) flat out gives away the ending!