Blog Image is a confusing term, some think of it as images for your blog and others, such as Bryan Eisenberg, use it as reflection of branding and reputation management.  I certainly don't mean Blog Image Hosting when talking about Blog Image and Picture Perfect when Ask.com puts forth that:

"…we identify those sites that have a broad representation of images and topics, and then weigh more heavily those sites with topic authority. As a further step, we apply sophisticated image recognition technologies to ensure that the best images rise to the top. The combination offers the best in relevance and variety."

So you can see where Blog Images are being confused with pictures rather than Branding; but that's not what Bryan Eisenberg is talking about:

"…How would you feel if this banner for porn popped up next to your blog? I doubt David Sifry would publicly comment. I also wonder what these fine bloggers would have to say if it happened to them: Seth Godin

I tested to see what happens with Web Analytics blogs and it took me refreshing the browser about 10 times till I got a semi pornographic ad. If I extend that idea out, at least one out of 10 times, some banner ads that are inappropriate to a blog, set of blogs or my blog will appear next to the Technorati information on my blog or the blogs I'm interested in knowing more about.

I guess it got worse when Technorati founder founder David Sifry and several others have left Technorati recently.