Skeletor strikes again
Obviously, Skeletor has moved into Dr. Evil's secret volcano lair and is using his mind-control-beam-satellite to make female celebrities think that looking skeletal is hot (also known as Operation Ally McBeal).
That's the only explanation that I can think of that would cause someone like Anna Kournikova, who made a career of being hot and a hobby of playing tennis, to go from fit and smoking (above)to emaciated and bony.(below)
Belaboring the obvious, this is not a good look. Look at her arms, they look like she's 80.
Anna, eat a sandwich. You can have half of mine even.