Ops Center packs a lot of information into a browser window. The upside is that you have a lot of information available, but the downside is that some of the information is presented using icons that can be confusing at first look.
The incident icons are one example of this sort of concentrated information. If you select an asset in Ops Center, you'll see a set of icons in the top-right section of its display:
These icons indicate the number of critical, warning, and info-level incidents on the selected asset. You can click any of the icons to go to the incidents tab:
There's also another set of icons in the top left that give you a broader picture of the incidents in your environment:
The first two icons show you how many unassigned critical and warning-level incidents there are in your environment. The middle icon shows the number of relayed incidents. The right two icons show how many critical and warning-level incidents have been assigned to you (that is, whoever is currently logged in.) Clicking on any of the icons takes you to the relevant section of the message center.
The Managing Incidents how-to has more information about these icons and about how you can manage incidents in Ops Center.