So maybe you've never drawn from the nude model before. Or maybe you've done it a hundred times. It's an unusual situation that doesn't have precedent or parallel for most of us outside the life drawing group. How are we supposed to act? I've been going to life drawing sessions for years and no one has really ever addressed this to me. The assumption is that you should know already, but why would you?
The model is presenting themselves as a subject of study. We're there to draw the model and to learn from the process. But the model is also, nude, and being nude can be a vulnerable position. Maybe the model is very comfortable with their body. Maybe they're not so confident. Maybe they're sensitive about their appearance. These are things we can't really know.
It's good to make the model feel welcome. It's good to be gracious. It's good to talk to them like a person, just as you would anyone else. It's good to give them some space during the break, especially when they're in the process of covering themselves. But it's not a good idea to talk about their bodies. Even with the best intentions, this is a very iffy area. I've done it myself. I've made, what I thought, were innocent comments about the models appearance, but you can't know how those comments are going to be interpreted. No matter how the comment is intended, if it's about the models body, even if it's complimentary, even if it's innocent, even if it doesn't seem to be inappropriate, it's better to err on the side of just not going there. For example: “you have pretty hair.” or “You have beautiful eyes.” No matter how innocently intended, this is the kind of comment best to be avoided.
Even if you're not talking directly to the model, even if the model isn't in the room, it's best not to talk about how attractive they are. They're not there for your gaze, but for your study. This is a very important distinction. We've all seen beautiful pictures of beautiful people, and there's nothing wrong with seeing them as beautiful, but in the life drawing session, respecting the model and what they're there to do means leaving these kinds of judgements and evaluations behind.
But if you have made comments like these, its not necessarily a tragedy or disaster, but as a rule of thumb, it's best to try to avoid making them in the future. We want everyone's experience, including the model's, to be a positive one, and it's up to all of us to do what we can to to make this a reality.