I agree that the show was very leery towards the models, and then towards the designers for being so thirsty. But I'm not sure the designers were sexually harassing the models, in large part because their comments were made to the camera as confessionals, or to each other. Rewatching the sequences, these are the comments and their contexts:
When the models first arrive for measurements, we get the following:
Sebastian talks to the camera about how "the male models, they all are gorgeous," and thus he tells himself not to look but to focus on his work;
Tessa jokes to her model that she won't make his pants too tight ("because I will make the crotch ill-fitting and insane" is unspoken), followed by her confessing to the camera that she is "starved for straight males," and that the models smell good;
Lela and Renee ask their model is he's comfy wearing chaps, and Lela titters in front of her model about how measuring guys is different.
After the models leave, in the sewing room:
Tessa talks to Sonia about how the latter's (i.e., Garo's) model smelt real good, and asks who he is; Bishme jumps in and jokes about Fedex packages, and Frankie says that they don't need anything "swinging" as the models walk.
The next morning, Bishme and his mom talk about his model's butt. The models then come in for their second fitting, and:
Tessa talks in a confessional about beginning to enjoy the challenge, though "maybe it's the male models in the room";
Lela blushingly tells her model that he can keep his underwear on; Renee laughs, and Lela says her bf might kill her;
So based on what we're shown, Lela and Tessa did make comments to their models' faces; for the most part, the other comments were kept between the designers, or the designers and the camera. Of course, this does mean that the models did and would eventually hear the confessionals. Were the intra-designer conversations too lascivious? Probably; the sewing room conversation about dicks was the most egregious. But in all I would say, albeit with some hesitation, that the atmosphere in the workroom while the models were there was fairly professional.