By Nathan Olivarez-Giles Facebook has begun automatically enhancing photos that users upload from the recently updated iOS app.What does that mean? If Facebook's enhancement algorithm think your pictures could use improvement in brightness or contrast, it will go ahead and do it. The first time you upload an image, a pop-up message appears warning of the change, with a promise of "brighter, clearer photos." Facebook isn't the only service to do this—Google+ has had a similar option for a while.While the enhancement itself isn't a bad idea, it's best to be aware of it.