It's the wrong way around on your PC.
Modern computers are smart enough to read the photo file as to what way around the camera was held when the photo was taken, and automatically display photos the right way up to you, regardless of the fact that the file itself is the wrong way up.
You will need to open your photo in a photo editing program and rotate it. Eg if you're a Windows user you probably have Paint in your Accessories menu. You can open it in that, and use the Image - Rotate menu to fix it. Then re-upload it.
Deb, in New Zealand