"Signage" pretty much implies the graphics capability has to be good, because it's all the viewer really sees of a digital signage system, even though there is much more behind the scenes. The focus should be on content displayed crisply and vibrantly with rich media blending capability, but not necessarily at ultra high frame rates or polygonal fill rates found in say the latest video games. The media may include video, graphics, animation, text, and tickers displayed in different windows on a display. Also, we recall that size and power aren't unlimited - many of these systems are relatively compact and operate without a fan, so implementing a high end GPU on a standalone card with lots of memory and its own cooling often isn't feasible. Integrated graphics technology often fits the bill in digital signage apps.