Pictorial: F(x) - 2

I know that I'm doing alot of F(x) post, but that's because they're the only ones posting online. And trust me I follow more than one member of each group on some kind of social network. But never mind that, F(x)'s Amber posted a picture with fellow members Luna and Krystal.
In the picture, Luna and Krystal are posing while Amber takes the picture. "Practice" is the caption. It seems that Luna, Krystal, and Amber are practicing for a performance, maybe for their song "Beautiful Stranger".

"Beautiful Stranger" is featured on their latest mini-album Electric Shock and features only Luna, Krystal, and Amber. 

From Left to Right: Krystal Amber Luna

PS. B2ST intro coming up!!!