Ugh. Without more context I can't be sure, but I'm guessing it's a reference to a crude and sexist practice. It's something that has existed for a long time, but was popularized by the 1979 movie, "10." It refers to grading women on a scale of 1 to 10, in terms of raw physical attractiveness and nothing else. It's like a beauty pageant without any pretense at judging talent. "A perfect ten" means a sex goddess... like Bo Derek, was, herself, in the movie "10." Nowadays I think it is applied to men as well. If so, it's demeaning to men, too. When do we use it? Preferably, we don't use it.

We often grade things on a scale of 1 to 10 where 1= worst and 10 = best. A ten is a perfect role model or example of something. For a woman to be a 10, she would have a perfect, slim, sexy female body shape with a lovely face and beautiful hair.