Monica Schipper/Getty ImagesWhile Publicis Groupe posted better-than-expected Q2 earnings on Thursday, the France-based advertising agency holding company warned the next quarter is going to be "difficult." Last year, Publicis lost a number of huge media-buying accounts, including the mammoth $2.6 billion Procter & Gamble North America media business, the Honda media account in Europe, General Mills, and Coca-Cola. It picked up some sizeable briefs along the way — like Visa, GSK, and Taco Bell — but Publicis CEO Maurice Lévy told Business Insider that nevertheless, Q3 will mark "the moment of truth and the most difficult moment of the year." But there are still plenty of reasons to be cheerful, according to Lévy. Last December, Publicis announced a major reorganization that saw the business split itself into four separate divisions — Publicis Communications, Publicis Media, Publicis Sapient, and Publicis Healthcare — designed to help its hundreds of agencies — from Saatchi & Saatchi, Starcom, Sapient Consulting, to Leo Burnett — work better together under its new "power of one" concept. That's improved the scope of work it is offering clients, Lévy explained.