Today I saw this banner on StackOverflow
I had to make a huge mental effort just to get that the gray portal that holds the question text is in fact an Android device. The reason is it has proportions of an iPad-like tab - - very close to a square - but most Android devices are smartphones and smartphones have slightly different proportions - less square. Also the gray portal completely lacks Android-specific hardware buttons that make Android devices distinguishable from say mobile Windows devices (the latter have different buttons).
IMO the banner needs improvements. My suggestions would be the following (I myself lack drawing capabilities):
- make the thing more elongated (less square) - something like HTC Incredible S proportions
- add margins on the "top" and the "bottom" (if held in portrait orientation) as real smartphones usually have
- add hardware buttons
- change orientation to landscape so that there's more room for the text
- bring the "Android Enthusiasts" caption out of the device image - place it beneath