I would say it means exactly what they say - you have a lovely and relaxed little bubba! It is always hard to know what to make of doctors comments or actions. At one appointment my doctor was worried about the heartbeat of my little one as it seemed really fast but prior to going in bubs was doing backflips and all sorts of crazy stuff so I wasn't too concerned as I knew she had just been really active. The doppler the dr was using didn't actually measure the HR you could just hear the sound so she timed it and worked it out and said it was all perfectly normal it just sounded fast. Then at my last appointment the dr had trouble finding the HB! Again I wasn't worried as I had felt her moving all day, turns out she was just a lot lower than the doctor expected and when she found the HB it was perfectly normal and healthy, very strong in fact.

I agree with others that if there was ever any reason for concern you would be more closely monitored but it sounds like everything is just perfect!