We've striven to let him watch himself in the mirror for a few minutes several times a day, because he is obviously getting some enjoyment out of it. And even if he isn't, we certainly are enjoying watching him watch himself.
I've decided that babies would make the best research projects. What is research, but watching something endlessly to make sense out of it? Babies are excellent for this.
And while I didn't get a photo of it, Jacob is also learning to reach out for things with his hands, to try and grab hold. The bathroom mirrors have tiny squidgy handprints on them, and somehow I don't mind.