"Couture" is the French word for "sewing" and in the fashion industry the term "haute couture" (lit. "high sewing" but more commonly translated to "high fashion") is often shortened down to just "couture". Haute couture, or "high fashion", refers to custom made clothing commonly made of expensive fabrics and time-consuming detailing and tailoring skill work. Haute couture costs exorbitant prices because of the demand on resources and skill level, and represents not only the peak of culture and style within fashion but also the decadence of wealth.
"Selfie Couture" is a pun combining the high fashion concept of "couture" with the common phrase "selfie culture" - which is generally viewed as an expression of low-brow vanity, enacted by duck-facing, superficial teen or young adult women - in order to evoke the image of combining these two disparate concepts (incredibly extravagant and highly cultured fashion that takes months of painstaking work cultivated over a life time of honing skills in sewing, with the instant gratification mass production of vanity) and creating a new idea of a culture of women bringing the idea of high fashion to a modern, technological age.
And puns don't care about grammar, Herr Linguist.