ShipScript has been an eBay Community volunteer since 2003, specializing in HTML, CSS, Scripts, Photos, Active Content, Technical Solutions, and online Seller Tools.
All photos are stored on cameras and phones in the default "landscape" orientation. On an iPhone, the default orientation is with the dimple on the right, and if you hold the phone in some other position, you will have a rotation issue for eBay.
The camera or phone will set a flag on the photo to indicate which side of the camera or phone was downward when the photo was taken. Many computer programs, and some browsers, know how to read that flag and will display a photo that is rotated back into the position your camera was held.
eBay does not recognize the rotation flag in a photo and strips that data away before the photo even reaches eBay's servers. That is why the photo always appears on eBay in the default landscape shape instead of a vertical shape. Thus the image, not just the flag, must be rotated before sending to eBay.
If you want to avoid rotating your photos, hold your camera in the normal position or hold your phone with the bottom dimple to the right. That is the default landscape orientation for all cameras and phones. Any other orientation will require a rotation, either in the phone/camera editor, desktop editor, or eBay uploader/editor.
eBay's photo uploader does have a rotation feature. Look on the photo edit screen when your image appears on your listing form, and rotate the image on the uploader screen. In some cases, the photo may appear correctly rotated on the screen, but won't arrive on eBay that way. If you know a photo was taken sideways, and you typically see sideways photos (if you held your phone vertically), just rotate it all the way around even of it looks okay onscreen and eBay's image uploader will make the correction.
Your iMac photo editor should have the ability to rotate and save a rotated version of the photo, but you may need to crop a little bit (or perform some other minor image task) to force the editor to write a new image instead of simply modifying (or not modifying) the rotation flag.
