Vietnamese chicks and hand gestures

[lpcs1]

This japanese M.M. Dude makes excellent nightlife reviews all across east and south east asia.
...and well it came to my attention that a lot of vietnamese chicks made this interesting hand gesture with their thumb and finger, as shown for example in this video. Do they signify that they're "available" for money?

Any of you guys have experience there? any tips?

 

[Happosai]

https://en.wikipedia.org/wiki/Finger_heart

BTS, Twice and a shitload of other Korean idols (male or female) use that during photoshoots.

 

[jane2man]

that is love sign dude....