During the picture taking process, we need to consider a number of things. Among them are lighting and angles. The picture below is the Cinderella Castle at Disneyland, Tokyo. What they are trying to achieve here is Hidden Mickeys and there's nothing wrong about it. Hehe.
Well, it's all about the tricks of the light and angles. And also the sun of course! I'm sure the designer of Westminster Bridge was not trying to achieve Hidden Mickeys in the first place! ^____^