Apple appear alone

I have iPad 3 running iOS 5.1.1 suddenly it stopped for a while and a black apple appeared.Any way the iPad works again after few seconds. What happened ?

 

Haven't seen the black apple on my iPad, but when starting up, My Macbook has a black apple for a few seconds. It goes away also after a few seconds.

 

I've never heard of that happening. When starting or reseting you usually get a white apple on a black background.