I don't know why this happens - photos will be correct where I'm uploading from but once uploaded here random photos will be sideways. I've seen others here having the same problem. The fix... Upload your pics and 'save media'. Click on the photo so it opens in large version. Immediately above the photo on the right side you will see 'media tools'. Click on that arrow and you will be given the option to rotate your photo. You have to do this individually but at least you can do it. Now you can copy/paste the link to the image like always and the photo will be in the correct view.