Image search keywords – a question answered

I got a question from one of my readers on my post Optimizing image search traffic :

Yes, helpful post indeed. A question – once you are getting traffic from images, can you tell what keywords are driving the traffic using Google Analytics? Using GA, is treated as a referring site, without any information about the keywords that found the image. I’d like to know what keywords the image is being found on.

My answer:

As far as I can see, keywords gotten via image search are shown / counted as normal keywords.

The real world example I am basing this on:
One of my sites is getting a lot of hits via the keyword “Schnörkel”, which means something like flourish or embellishment in German.

This word does NOT appear anywhere on the page except for being the name of a small divider gif.

In that case, I renamed the image to div1.gif, as the traffic for that was no traffic I particularly cared about.