If I want a quick peek at an image or screenshot, I want to do so immediately in Photo Viewer, not wait for the Photos App to load 'Pictures', OneDrive and all kinds of other destinations first.
I can open my browser, navigate to The Weather Network and check the weather faster than the Weather App can load!
It doesn't do it on my machine though, the icon updates back to the main screen.
When I use a program, I want to be sure that it can do everything I want it to do. If not, I find one that can . . . that's why I pretty much stay out of the Store. Come to think on it, a lot of what's in the Store used to come with Windows.