Powerfull, thought provoking and memorable. That's what can happen when you use the space that isn't there in graphics. Negative space. It's a wonderful trick that engages the mind of the viewer far more than just a great image. It's somehow captivating at a deeper level, because it makes your mind work out the visual trick. Because humans are hard wired to recognise silhouettes (it's a predatory response, earlier homonids needed to quickly work out friend from foe or prey items). You spend more time decoding and so therefore remembering, and because of your success, you get that cheeky warm feeling. The payoff - a smile and the opportunity of lodging your brand alongside it. So maybe next time your have a brief on your table, think more negatively, it might end up have very positive results.