It's clearly a joke. We get it, you think she's attractive. 180 is enormous for a female tennis player.
When Serena was in shape she was one of the most dominant athletes on the planet in any sport. She's gotten lazy and continues to reach the finals of tournaments on her athleticism alone and the fact that the women's competition in tennis has been so weak year after year.
She won - what was it, the '09 Australian Open? - looking like she sat around and ate chips all summer, which she probably did.
If she had a Jerry Rice mentality she would be even more dominant.