Uncle Buck: the three mystery men in the mail slot?

Watched Uncle Buck this weekend. TiVo’s scheduler gave it two and a half stars, which is dead wrong in my book: Uncle Buck is comedy gold.

The movie occasionally veers into the surreal for comedic effect (e.g. the clown getting punched down and then bizarrely levitating back to vertical for another hit). One such instance is when Macaulay Culkin is peering through the mail slot, trying to spot Amy Madigan; instead, he keeps seeing nothing (she coincidentally sidesteps the slot each time he’s looking through), except on one occasion, when he opens the mail slot and finds himself face to face with three men who appear nowhere else in the movie.

Who are these three men? Are they supposed to be somebody famous, either present day (i.e. 1989, when UB was released)? or are they just random men thrown in for another surreal comedy moment?

One of my favorite movies!
I always figured the mail slot guys were either just a funny visual meant to round out the scene, or, more likely IMO, muscle sent by a loan shark (or similar) looking for Buck.
One of the fellas is [credited on IMDB](Scary man in mailbox slot (uncredited)) as “Scary man in mailbox slot.”

I always thought it was a reference to Home Alone, which Macaulay Culkin starred in, but I see Uncle Buck came before that. I assume then it’s just supposed to be imaginary robbers.

It’s just a scary flight of imagination for the kid.

You left out the best part: that even his MAKEUP goes all kiddywumpus from being punched.

That’s what I always thought to.

John Candy at his best