We do Earth observations for two reasons: first of all, it's psychological support for the crew to be able to look at our beautiful planet and to see where our families are. They're not so far away.
On the other hand, we do a lot of Earth observations as scientific activities, photographing specific ground sites over the years that the space station has flown. Of course, we hope to see the changes in nature over the 10, 20, and 30 years that we will operate the space station.
Here we see a beautiful picture of Paris with the Champs-Elysées. Here's a very similar city, but in another part of the world. It's Medina, in Saudi Arabia.