Celebrity makeup-What is that white stuff they put under their eyes when doing their makeup?

I've seen that when people get their make up done professionally a lot of the times they put white stuff under their eyes while doing their make up. What does it do? What is it called? It looks like it's concealer but it is white. Where can I buy it?Celebrity makeup-What is that white stuff they put under their eyes when doing their makeup?
Eye shadow base?Celebrity makeup-What is that white stuff they put under their eyes when doing their makeup?
I'm pretty sure it's regular powder (like baby powder). You can get it at almost any store with a cosmetics department. I saw Tyra Banks use it on her show when she was doing her makeup. Its used to put under the eyes while they are doing their eye makeup so that if loose eyeshadow falls down under the eye, they can get it off without smearing or ruining their concealer/foundation. I've tried this trick, and it does help!
its like an eye brightener and its supposed to make your eyes pop and make you look more awake you can get it at like sephora or any make up stores pretty much.
its either white eyeshadow but probly consealer
i think it's undereye conealer(:
possibly primer?? helps so concealer doesnt clump, crease etc. you can get it at like www.sephora.com
i think it is a silica based powder to seal their make up. Make up forever brand makes one