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Why is my image rotated when I upload it?
Certain software (like Preview or iPhoto on a Mac, or certain Windows photo viewers) automatically rotate the image to the correct orientation when you view it. The software recognizes meta data embedded in the image that tells it how to display; browsers do not recognize this meta data.
To solve this, you can open the image in Photoshop, ImageReady or any other image editor, rotate it and save it again. This should save the correct orientation. Gimp is one free option that can properly rotate an image. Edit your deviation and upload this new image file.