You may have spotted Cadbury's new Dairy Milk poster, which is cleverly done, showing you how much of the poster would be milk if it was the same size as a chocolate bar (if only).
Shortly afterwards a Nestle's Milky Bar poster popped up nearby, seemingly in response. The first rumblings of a chocolate bar war perhaps?
Or - more likely - as I found out a few days later, a reaction to World Milk Day? It seems too much of a coincidence not to be, seeing as they appeared around the same time. But no mention in the small print. And not a hashtag in sight!