Sometimes an image that appears right-side up on your computer can be upside down or sideways once you upload it as your profile picture. Why does this happen?
The reason for this is that some computers will automatically rotate images which are not the correct way up when you view them. So when you open the image to view it, even though it is actually upside down in the file, your computer will show it to you as right-side up.
How to Fix It
To fix this, you will need to open the file in an image editor (not an image viewer) and rotate the image. Once you open the file for editing you will see that it is actually in the wrong position. You can rotate the image on your computer using Paint or Photoshop or any number of photo editing programs.
Instructions for Using Paint
Once you have opened the image file in Paint or whatever program you have, you can rotate it to the correct position and save the file. The steps for this will vary slightly for every program, but it is a very common feature of photo editors and should be easy to find. This is what it will look like in Paint, for example:
Once you rotate the image and save the file, the image should now be the correct way around when you open it up in a viewer or upload it to your profile.
Be sure to save the file after rotating the image to the correct position, then upload the newly saved file as your avatar!