Good point and very well-said. I have a sudden urge to start using my pony reaction images outside this thread. forget da police.
I wouldn't go out of my way to do so, which I assume you wouldn't either, only when I felt I would do it in a similar situation with another funny image, but there is absolutely nothing wrong with posting an image (reaction or not) for relevancy or to have a good laugh with others.
People have done it with spongebob, monty python, justin bieber and so on just to be funny or to have some fun.