I was using the VO learning in System Pref and went away from my computer for a few min. My screen was black when I got back and I clicked the mouse to wake it. Then it went black again and I clicked the mouse to wake it again it said “Two system dialogs displayed “. What is that?
It is a feature of VoiceOver to alert you to the fact that system dialogs have been displayed (this text can be read by the computer voice for you).
You can find the dialogs by tabbing through the open windows (or if you can see sufficiently, they're probably already displayed on the screen).