The poses are very intentional as the real catalog has slight differences than this online version and a forth person has either been photoshopped into the picture or was present for this alternative picture. The differences are very subtle so these exact poses are what the catalog wanted to present.
The party message and the necessity of "alcohol" or drugs to "chill" and "sex" to have fun are very clear. I know that sounds "paranoid parent" but its intended to be more of a pure criticism of their marketing approach.