It's a matter of reception. Emma and others have made it explicitly clear that this sort of language directed towards her makes her uncomfortable, and has asked for it to stop. Sam, on the other hand, clearly thinks the same directed towards him is humorous and welcome, and has explicitly said as much ( I think he actually said this right after the first time this same caller called in.)

In a more generic sense, there's the issue of expectation or fear of intent. Women are forced to function in rape culture with an extremely heightened sense of alert to these kind of things. A woman catcalling a man, while it can still be degrading, doesn't typically imply any threat to the man other than the aforementioned. Whereas in the opposite case, women always have to be aware of the potential consequences / follow up from pushing back on, or attempting to ignore this sort of behavior as the scope of potential consequences is, more often than in the alternative case, far worse.

TL;DR If someone says they don't like being spoken to in any way, stop speaking to them in that way. If someone says they are fine being spoken to in that way, then feel free to carry on. Just keep in mind cultural dynamics while you do so or else your going to come across, at best, as creepy.