Just want to told you what happened in Germany. I have analysed the top-5000 keywords for images (Germany). This is what I could read out of it:
Four weeks ago Google changed the image-search algo fundamentally: freshness became really important. The effect was that news-sites and shops won a lot of new images in the top-100. This period took two weeks and a lot of small sites lost images and positions.
But one week ago Google turned this back.
At the same time (one week ago) Wikipedia lost about 10% of their top-positions. The news-sites and some shops also felt down.
In consequnce this week many small sites and galleries won a lot of positions.
I have nor idea if this is important for other countries. But perhaps it helps somebody ...