For the past month or so, we have added saying night night to pictures of family to our bedtime routine. Alex looks at the pictures and says "night night Nana," "night night" to grandma, and so on through all of the family, planting big "mmmmwah!" kisses on each of the photos in turn. So he definitely gets the idea that people can be in pictures.
Tonight, he pulled out our wedding proof albums and kept pointing to "Mommy!" and "Daddy!" At one point, there was a page where there were 4 pictures of me and he counted "twoooo-theeee Mommy!" (he doesn't seem to say one because that word is apparently reserved for Mommy or Daddy, and he hasn't quite gotten past 3 either). Then he saw a picture of our friend Jason, with whose family we spent the afternoon at the aquarium today and who had served as one of Mike's groomsmen. And incredibly, plain as day he pointed to the photo and said "Jason." Not once, but several times to confirm.
Once again, I am reminded that I must watch what I say in front of the little man. We did not try to teach him Jason's name, he just picked it up from the adult conversation.