This is common in asian countries. Thai people's idea of conventional beauty is pale skin, small face, big eyes, small nose, very thin figure, flawless untouched skin. This is pretty much the same in other Asian countries. All these attributes in the past have been associated with wealth and superiority; poor people worked outside in the scorching sun and got tanned, whereas rich people worked in air conditioned offices and stayed pale, or even lived abroad in western countries and didn't get as much sunshine. It's an outdated idea of beauty, and is slowly changing (finally).
I'm surprised that you people are acting shocked about this when here in England, young men and women are spending precious time and money trying their best to get tanned, constantly dye their hair, wear make up to cover spots, get various surgeries to conform with their particular idea of beauty. My friends think pale skin is ugly. I beg to differ.
I hope you guys don't get a horrible idea of Thai people because of this. We're slowly learning. We just haven't got to the politically correct stage yet. Bearing in mind, I've been the victim of racism in England several times myself. It's everywhere. Not just in this poster.