How do they do it?

G’day

The way they fade in the image on this site is awesome.
Does anyone know how it would be done?

http://www.maxfactor.com.au/

Click on the link to play and you’ll see what I mean (photo of woman)

If anyone knows could you let me in on it?

Thanks

BeeKay

Thanks guys. I’ll give it a shot. Will let you know how I go.