I was once preparing photographs for someone writing a book on a local football club.
They had 2 aerial photographs of the club's stadium from different eras and wanted to put them beside each other in the book, making a nice comparison between what it used to look like and what it looks like now.
One of the aerial photographs was taken looking from the opposite direction of the other however so the person who was asking me to format the photographs wanted me to take one of the photos and "rotate it 180 degrees so it's looking at the stadium from the same direction as the other".
I tried explaining that such a thing was impossible, you can't rotate a photograph such that it looks like it was taken from a completely different location. But he was quite insistent that I simply rotate it 180 degress. Which I did.
He was happy with the results when he saw it on my computer screen. For the life of me I couldn't explain that he was just looking at an upside down aerial photograph of the stadium. He insisted it was fine because now what was now the corners of the pitch are in the same location in both photos so it looks like they were taken from the same angle.
I had to actually zoom in on the photo and show that the buildings were upside down, the people in the stands were upside down, the goals were upside down, the advertising around the pitch was upside down. It was just an upside down photograph, not a photograph looking from the opposite direction.
The same person once gave me a photograph of the back of someone's head and asked me to rotate it so they could see their face...