At this point, I can circle back to volleyball as a good example of how this extends even to traditionally feminine sports that have objective rules. I pull up a web browser and do an image search for "men's volleyball":
I point out that most of the images are action shots, either of competition or celebration within competition. Then, I do a search for "women's volleyball":
I ask the students what differences jump out at them. Without fail, they notice that fewer of the images are action shots and that most are posed and, of course, that the women are wearing far less clothing and the clothing they are wearing is quite tight and revealing. I ask them why this would be since the men and women are playing the same sport with the same rules on the same courts. It's not as if having more or less clothing is somehow offering a competitive advantage. If that were the case, it would be universally adopted. Instead, we see a prime example of gendered expectations; even in an objectively defined sport, we insist that women perform gender in a way that allows them to be objectified.