The native taskbar button uses a slow glowing/flashing orange animation effect to indicate a Window needs your attention. The native button has a glass effect over it. The display fusion button is does not animate and does not seem to have the glass effect as you can see in the screenshot. The native one is almost fully orange (in it's glowing animation cycle) but still looks different than the displayfusion one.

I don't have transparency enabled in my settings. Sorry for nitpicking It was different enough to catch my attention immediately. In fact I prefer DisplayFusion's over Win7 but I suppose it should match the native button.