I think merely telling you the conversation that just happened in our house around this photo is enough to explain it.
Me (handing Bruce a print out of two photos put next to each other) - Look.
Him - Cute!
Me - I think you're missing the point. Which one is Meg?
Him - You mean it's not the same person?
Here's me in that 12-18 month age range on the left. Megan at 18 months on the right.