Ask HN: Chrome store and small icons

Why does the chrome extension webstore use the ugly looking small 12px by 12px icons? I do see that some apps use a larger icon but 99% of the extensions out there are tiny little icons that you cannot even see or make out. I do see that some extensions use the larger one ... Searching docs though, can't figure out how. Please share if anyone knows how to use larger icon images for the chrome play store!