This refers to whether or not the client is currrently online or offline.
Enabled = Online
Disabled = Offline
For this report, select the Advanced Settings link and you set the Online Status to show what you need. By default it is set to All.
To test it out, set the Online Status to Online and export the report, you will see the Status column now shows Enabled for all. Do the same for Offline and all will show as Disabled.
Kinda funky but is what it is...