I can confirm it was a bug. I have observed the game randomly adding character value if you cancel mid activity an activity that raises a character value and already have queued and close by will transfer the gain to the next activity. I got to happen with both the karaoke and playing Sims Go on the computer and with multiple traits. It is a bug and it is very random. Neither Karaoke nor Sims Go raises any character value without the immediate canceling of activity that would normally and at best only does so rarely. I have gotten the bug to repeat but less then a third of the time I tried. I spent most of the day messing with it. Good news it has next to no effect on game play and can be seen as a random bonus. I haven't got it to lower a value just randomly raise one. I am sorry I miss reported my finding. When I seen empathy going up while singing karaoke I got exited and din't verify the result.
But hey I did Identify a extremely minor bug with little or no game relevance. It doesn't even give you a funny screen shot.