In the Windows 8 Consumer Preview, the App Preview version of the Photos app provides a basic but attractive interface for viewing photos found on the PC, or in online services such as SkyDrive, Facebook and Flickr.
In this way, Photos closely mirrors the consumption-focused interfaces of Metro-style apps and the entire Metro environment, while relegating more advanced experiences such as acquiring photos from cameras and memory cards, editing photos, or creating video-based slideshows, to more powerful and complex Windows desktop applications. This odd dichotomy is, of course, a hallmark of Windows 8's overall design. But it means that Photos, like other Metro-style App Previews, is pretty limited, by design.
It's also pretty limited even within the scope of consumption-type activities, really. Yes, you can view photos, and, yes, you can trigger photo slideshows. But there's no variety here at all, no slideshow themes or configuration options, and you can't mix and match between the different photo sources--the PC's Pictures library, SkyDrive, Facebook, and Flickr--at all.
On the surface, Photos hits all the high notes. It offers a nice, dynamic live tile that animates between various photos in your collection, for example, or if you'd prefer, you can set a favorite picture as the tile's sole image.
The app itself is simple, offering a nice tile-based interface whose home page offers obvious launch points for the four supported photos sources.
Sub-screens are equally visual, with the same nice tile-based design, offering obvious navigation choices.
As for views where actual photos can be found, the onscreen real estate is wasted. On a typical 1366 x 768 screen, you can see at most three to five photos, depending on their orientation. But normally, you see only two. The only option here is to zoom in using pinch zoom or CTRL + the mouse's scroll wheel. That will provide a grid-like view for the photos.
Upon viewing a photo, you have other limited choices. You can launch a slideshow, set the photo as the app tile, set the photo as the lock screen, or delete.
(If you're viewing a photo from an online service, you will see an addition choice related to viewing the photo on the service itself. Tapping this button will launch the Metro version of IE 10, which will navigate to the page containing the photo.)
There is one fairly advanced feature involving slideshows. Within one photo source only--you can't mix and match between, say, Pictures library and Facebook--you can arbitrarily select photos in different folders. As you do so, they are stored in a File Picker-like basket.
Once you've selected all the photos you want--mixing and matching between different folders if desired--you can then trigger a slideshow that includes all of those photos. That's nice, but there are no other options. You can't change anything about the slideshow while it's running.
Printing and sharing occur normally, via the standard Metro-style charms, as does Search. If you open the Search charm from outside the Photos app and then select Photos from the list of apps in the Search pane, you get the zoom-type grid-based view of your Pictures library, presumably because it provides for more photos on-screen at once.
In Settings, you can determine whether slideshows shuffle the photos and disable the online account(s)--SkyDrive, Facebook, and/or Flickr--you don't use. That's about it. (Connecting to Facebook and Flickr may require you to first "connect" those services to the app, using a web-based interface. Sometimes, these connections are previously available, however, if you connected them previously through your Windows Live Profile.)
Overall, the Photos apps is simple and incomplete like other App Previews, and needs some obvious features to make it truly valuable. High on the list are support for more online services, the ability to share photos on various online services, advanced slideshow configurations, simple photo editing capabilities, and a Metro-based photos acquisition interface. That's a lot of stuff, I know. But I don't see how Microsoft can expect tablet users, especially, to use desktop apps like Windows Live Photo Gallery to accomplish these tasks. And today, in App Preview form, Photos just doesn't cut it.