Has to do with the length of the shelf, Jim. If I stretch it, that disappears (if I'm reading your thoughts correctly).
@ Uvah: subdocks here: https://forums.wincustomize.com/405914/page/1/#2896945
Quoting Uvah, reply 65Are there docks for the dock?
Nexus features 'sub-docks', which can be nested into an infinite number of levels. This allows you to categorize applications in the dock (i.e.; create program groups).
The icons for the sub-docks don't have to be all the same like in Doc's screenshot, by the way, you can customize them just like you would any other dock icon: by dropping a PNG, ICO or TIF image into them.
Indeed. I left the Nexus Icon by design, to show Dock/relevant subdock.