I can't answer that specifically; I can say that when we had this in our guest room, guests would frequently turn it face-down either because it wouldn't darken fast enough or it didn't get dark enough and they found it distracting. (I don't have it any more.)
It will show them as you load them. When we saved the portrait pictures to the drive, the windows viewer allowed us to save them properly (left click on picture and click rotate clockwise). Then all saved pictures show properly.
I've noticed it sometimes no longer reads the memory card I have put in there and I have to regularly rotate cards out. I am currently looking at other frames to buy since this one has failed nearly all my expectations for it.
I own a Mac and use it to update photos on the SD card to use in the frame. No need to connect the frame directly to the computer. It just uses your SD card so it doesn't matter whether you have a Mac or PC
You'll have to crop the pics with a digital picture editor so their aspect ratio (length vs. width) is the same as the frame, or else black areas will show either along the top and bottom, or along the sides.