Williams, 28, who is set to regain the number one world ranking when the WTA issues a new list on Monday, also said she was "super flattered" to be one of the athletes featured on six different covers.
"ESPN had a 'Body Issue' and they told me I had a great body and they wanted me to be on the cover so I was super flattered," she told reporters late Thursday after a three-set loss at the China Open to Russia's Nadia Petrova.
"But I wanted to do it really classy and not trampy. I thought it was a really tasteful picture... I love it."
A smiling Williams -- wearing nothing but red lipstick -- appears on the cover with her arms covering her breasts and her left leg strategically placed.
Other stars featured on the covers include NBA centre Dwight Howard, Minnesota Vikings running back Adrian Peterson, mixed martial artist Gina Carano, NASCAR driver Carl Edwards and amputee triathlete Sarah Reinertsen.