http://www.google.com/imgres?um=1&hl=en&rls=com.microsoft:en-us:IE-SearchBox&biw=1366&bih=557&tbm=isch&tbnid=ZE6A5OTEGyQaSM:&imgrefurl=http://www.businesspundit.com/the-unique-origins-of-25-popular-products/&docid=9NE60Zmw1EeC9M&imgurl=http://www.businesspundit.com/wp-content/uploads/2009/09/zzgatorade.jpg&w=425&h=441&ei=gbJ5T8iRNuS20AGL8_C9DQ&zoom=1&iact=hc&vpx=504&vpy=2&dur=6712&hovh=229&hovw=220&tx=118&ty=53&sig=112783908998267108374&page=1&tbnh=116&tbnw=85&start=0&ndsp=25&ved=1t:429,r:11,s:0

Above is a link to a picture for a Gatorade advertisement.

It shows an athletic woman drinking Gatorade.
She is portrayed to be sweaty and tired and in need of something to replenish her.
The look on her face while drinking the Gatorade is made so it looks like she is enjoying the Gatorade more than anything else at that moment.
they have the Gatorade pointed toward the camera so you can see the label.
The picture is trying to say that Gatorade is refreshing and thirst quenching and they aim there sales towards athletes so they use her facial expression with the combination of her sweaty and in workout clothes to show how athletes would enjoy this drink.