It's true that you can't know about criminal activity from pictures, but I do think you can tell when the royal personages we follow are happy or unhappy. I remember thinking "something's wrong" looking at the photos of then-Princess Alexandra of Denmark and Prince Joachim months before their separation was announced. Even consummate professionals have a hard time looking truly happy when they are not.
Cristina and Inaki were so happy when they were first married, right up until about the birth of Irene, or maybe a year after that. Since then I've wondered, is Cristina just aging, or is there some reason she looks different to me?
When you look at a picture, you can see a smiling person or an unhappy face, but you dont know why someone is showing an emotion. The example that ive read the other day was people telling that cristina and felipe were not longer close like they were in the past because she didnt like letizia, now people says it was because of Inaki. People arrive at a conclusions that sometimes is true and most of the time it isnt. It is true that for many people their body language speaks louder than words, but royals most of the time have learned to act appropiately for the occasions and that implies hiding their emotions and showing their best face. When they are unable they dont participate, Princess Masako is the best example.