It's part of the UI. Specifically, if you wanted to change it, you'll need to change the UI\Console\YourRace\YourRaceUITile03.blp where YourRace is the race that the UI belongs to. In your example picture, the race would be Orc.
To change this, you'll need to import a blp that would replace that part of the UI.
You should change the path to UI\Console\Orc\OrcUITile03.blp .