Cindy is fascinated by Lenas career, since it could be Cindy herself who could get that attention and liberation.
Lena and Cindy are two very beautiful women and the center of the attention, naturally they ignore each other at best and become rivals at worst. Its different with Ivy, since they spent their youth together, she doesn't have that time with Cindy. Instead, all Lena knows about her is that she is Axels new project, which is a negative association on every path: If she hates Axel, she assumes she is his next victim and foolishly so if Cindy allows this and disregards Lenas advice. And if she desires Axel, Cindy is obviously her rival.
In general, Lena voices her attraction to man and women in her head whenever she find them attractive. Its clear with Ivy, she gushes over Holly, she finds sleeping with Louise very curios, she can tease Emma when they first hang out on their shoping trip. She never gave one positive thought toward Cindy beyond the neutral observation that she was beautiful, which was less emphasized because Lena could be attracted to her, and more so to point out that Lena recognizes Cindys social standing and potential model career.
In summary, Cindy and Lena don't know each other to justify a romance. Lena only sees her as a proxy to Axel, Cindy only as a proxy to modelling.