By taking two or more pictures of the same subject / the same place at different points, you gain an ability that photography itself is lacking; you get a sense of time. Instead of capturing a single moment, you can link these images together and thus get a sum that is larger than the individual pictures themselfs.
“By the time he shot the same building again in 1971, the sign had been changed — the establishment’s name and the Coca-Cola sign now appeared in a single board” – Simply by having two pictures and looking at the differences, you might start to wonder what has led to these changes and this way you start to form a narrative in your head. This gives us a different way of telling stories through pictures, than if we simply wonder what a single picture tells us about the current situation as that picture was taken in a split second. However, one thing to keep thinking of is how to keep the individual pictures compelling as well, since I feel this approach only truly adds something to photography if we have already interesting pictures which then become something even larger by being having a certain juxtaposition of various pictures. I don’t find the pictures at the lake compelling at all.
An interesting point for a discussion: If we by taking pictures at different times, what can we achieve through this which we couldn’t just achieve with film? For me, photography is about freezing a moment which is what makes it differ from film. What does this add?