Behold another “Chicken Wings Classic”! This one came way from back in the day, from before the first book even, when we were very aviation specific. The joke plays on the tendency of certain pilots to “duck-under” the minimums on an IFR approach (descend below them) to take a peek to see if they can see the runway. It is based on a belief that there is always a built in “fudge factor” and also the unwillingness to go missed and shoot another approach.
This is obviously very dangerous. In this case it seemed to work out for everybody with them all claiming they broke through the clouds “right at” the minimums.
Did I explain that right?