My ex-father-in-law had his own interior decorating business. One day, he came home with a strip of wallpaper. "This is what I put in a lady's house today," he said, "what do you think?" The wallpaper was very pretty - a white background with little bunches of pink and blue flowers. Thing is, he was holding the strip so that the stems of the flower bunches were pointing upwards. We said "It's nice, but aren't you holding it upside down?" He looked dismayed and said "Oh, NO!"
Hehehe - this reminds me of something my mother did. Their first house, which was built probably in the 1940's or 50's - had maroon and gray tile in the one teeny bathroom. the kind of tile that goes halfway up the wall, all around, and is one color, with the other as an accent. My mother search high and low for wallpaper to watch, and finally found some. Which was in the same color scheme, with foil, in a bamboo-like print (this was 1969 or 70). She is so proud of herself for finding it, and putting it up herself. As I said, it was a small bathroom, so not a lot of paper to put up.
After its all said and done, she kept looking at it, thinking it looked funny. Over a period of months. Finally one day, she realized, the bamboo was pointing upside down. Yes, she had put up the wallpaper upside down.