Google decided that was time to change the interface of their online store. If you went to the Google Play Store from your web browser today, probably you noticed a slightly changed app listing page. However, not everyone is seeing them just yet.
You will notice a narrower main column, with app info the similar app suggestions and other apps from the developer in a second column to the right. If your window is too small, that second column will move to the bottom. This means the content for the app you’re actually looking at will occupy less of the screen.
If you don’t have the new layout yet, just give it some time and than leave us your feedback.