She's right. I have to cop to it. I always straighten things on walls, even in places where I really shouldn't do it, like at the Phillips Collection in Washington, DC. It's a wonderful museum that bills itself as America's First Museum of Modern Art.
The Collection is in an old mansion and the day we were there, the staff was getting ready for some sort of event to be held that evening. As a result, there were musicians throughout the museum practicing for later in the day. The museum was beautiful; the music was beautiful; and the art was stunning. It's a wonderful place to see all sorts of great works by all the best modern artists and we were lucky to be there on that particular day.
However, because it is in a large old home, the museum comprises many, many separate rooms. At one point, I happened to be in one all by myself and I noticed that one of the paintings was crooked. I looked around. No one there. No cameras that I could find. So I straightened the picture. And left the room quickly in order to blend in with the other visitors. Nothing happened; no alarms went off, but I suppose it was not a great idea to tamper with great art.
Like the cat in the photo, I just couldn't help myself. Really.