Odd Problem

Hi everybody, just bought a 2004 toyota prius for the first time and I'm lovin it! Has 200,000 miles and I'm averaging 45mpg in ~35°F weather. My question is, I went to the gas station today and filled it up for the second time, when I went to start it, I pressed the parking button first by accident, then the power button while having the brake pressed. When I did this, the dash lights did not come on, no miles, mph, ready light, etc. But the touchscreen worked and said ready on the bottom. I put it into drive and it drove, with no dash lights at all. Is this come kind of mode? or is there something wrong with my prius?
It has only done this once so far, and my 12v battery has 86,000 miles to go according to the maintenance screen.

 

Thanks!