Elena -

This is a great question and you are smart to observe this cultural nuance. I watched the clip on youtube to understand better the context. The humor here is subtle. At first, Chandler is smiling and proud that she even noticed him at all, because she is a famous model. "Some guy" was a reference to him so he was initially just happy that he was noticed by her, and repeating the reference to himself with excitement. (This is kind of funny because it's pathetic that he would be excited for this). But then , as you noted, at the end is another joke where "some" changes meaning:

"I saw you with some guy" -- I saw you with some random guy

"Yes, he was SOME guy" -- when you emphasize the word SOME, then "some" changes to mean something great.

Like, if I said, "that was SOME chicken we ate last night!" it means that the chicken we ate was awesome.

"I met some guy" - random guy

"Yeah he was SOME guy" - awesome guy

Make sense? I know it's kind of confusing! But that's the joke. Hope this helps!

Steve

Hi Elena,

The joke is that some in a phrase describing a person can have two different meanings: 1) the meaning you noticed, of “random/unknown [person]” and 2) the meaning of “an impressive person with admirable personal qualities”. The famous actress is telling her mom, “I’m locked in this public place with a random person”, and Chandler, who is excited about being stuck with this attractive actress, imagines and hopes that her meaning starts with 1) and then becomes 2). That people will think he’s impressive because he was stuck with her, and that she will be impressed by him. (That’s why he tries to blow that bubble with the gum.)

Of course, this is just his imagination ;).

He is excited that she is speaking to her mother about him, but we are laughing at him because she calls him "some guy" -- meaning someone unimportant to her.

In this context "some guy" means a random person or a person that is not important.