If the photo you are adding a photo to your profile is sideways it is most likely coming straight from a cellphone.

This is due to the metadata of the photo being set to landscape when it comes straight from a mobile phone even though it was taken in portrait.

Metadata is how digital cameras and computers communicate and translate how a photo is displayed.
Essentially the computer is reading the photo as being landscape even though it was taken in portrait.

To fix this save the Photo to their computer. Make sure the photo is rotated corrected. Save the photo as a DIFFERENT NAME. This rebuilds the metadata and resolves the issue. Re-add it to your profile