I'm bringing this up again, as someone recently asked about it. It's the phone. When I researched it a couple of years ago it was just an I phone thing. I just looked up the data from a recent sideways pictures and it was taken with a Samsung. It makes a difference on if you hold your camera up and down or sideways too, ie: portrait or landscape. I'm not sure if the resize works, probably. You should resize your pictures anyway to post so they don't appear too large.
While I'm on the subject of pictures, I knew the picture was taken with a Samsung because of the EXIF data that is with the picture. If you take a picture with the gps tag ON, anyone , meaning bad guys, can tell where the picture was taken by the gps coordinates. If you take a picture and there is something in the picture the bad guy would like to have he can get the exact location the picture was taken. Any photo editing program will tell you the EXIF data for a picture unless it has been stripped.
There are free apps that will strip the data from you pictures.