Sorry, I misunderstood a bit. If you use Snap layout, an iccon over the program would appear to use Snap group. See the below thumbnail which says "group".
Snap groups: Snap groups are a way to easily switch back to your snapped windows. To try this out, snap together at least 2 app windows on your screen. Hover over one of these open apps on the Taskbar to find the snap group and click to quickly switch back.