If you take a picture with your digital camera or with your phone, you will get portrait or landscape images, depending on how you are holding the device. This works because your device has an acceleration sensor allowing it to determine which edges are at the top and bottom. These pieces of information are then incorporated into the image as an EXIF orientation tag.
Scrivito's new image processing system takes those pieces of information into account when generating optimized versions. So you no longer need to pre-process such images to make them look as they should with Scrivito. In other words: Down-scaled image versions will always be oriented as intended.