I downloaded the pic of the two people with drinks and it did indeed display upside down. I then opened it in Photoshop and changed the image size from 4032 x 3024 to 3840 x 2160 and saved it. This image then displayed right side up in DeskScapes. So, to test this theory, I opened a pic I had in Photoshop and saved it at 4032 x 3024 and it displayed right side up in DeskScapes.
Based on this info, I'm guessing there is something in the Meta data that forces it to display upside down. I have had this issue before with photos taken with my iPhone in landscape with the phone upside down.
If you have an image editing app, I think if you open it, make a change, and then save it, it will display correctly. The Microsoft Photos app will work. You will have to make some kind of change to it (like a small crop) and then save as. I tested this with MS Photos and it does work.