Last May during his keynote presentation at WWD’s Beauty CEO Summit, Unilever’s then-head of personal care, Dave Lewis, revealed the consumer products giant was “looking up the personal-care pyramid” to enter the higher-end segment of the market. Lewis left shortly thereafter to become chief executive officer of Tesco, but the company is making good on that promise — by acquiring the niche skin-care brands Ren and Kate Somerville — at a time when its primary competitor, Procter & Gamble, is looking to divest. Is this just the beginning? Insiders say Unilever has a “major initiative to develop a luxury portfolio of brands,” in the words of one plugged-in source. The operation will be based in London under the leadership of Vasiliki Petrou, senior vice president of prestige brands