Likewise, the notion that for a photo to be understood it needs to be seen in context is widely accepted. And, it is also true. But who defines the proper context?
In real life, photos are usually displayed without contextual information. Because they only "function" without it. Take this picture here (thanks for sending it, Pieter) that, without any additional info, might be interpreted as two political leaders (whatever that is) trying hard to convey the impression that they possess a sense of direction, that they know which way to go. This is the kind of analysis that usually passes for critical journalism but only falls into the trap laid out by the political actors shown in the photograph (or their advisors - not shown in the photograph).
Needless to say, this picture could be interpreted very differently. Are Brown and Merkel birdwatching? Do they point at a passing airplane? Or did they perhaps spot an eagle about to land? The fact that the man in the background doesn't fall for the show might indicate that we shouldn't either and would be well advised to stick to what the photo shows: Brown and Merkel gesture for the cameras.