Because it sure looks like it does. For my sites we disallow the images directory and the previews are all missing images which makes the site look wonky.
Is this the case and is there a way to allow just the preview bot to access images using robots.txt?
EDIT: It looks like the previews are generated both by the normal Google Bot and by an on the fly bot Google Web Preview as mentioned (briefly) on the Webmaster Central Blog.
By using a site: search and my monitoring software I could see when the bot hit my site and when this happened the images showed up just fine in the preview. So my guess is that the normal crawler ignores the images per robots.txt, but the preview crawler gets the images anyway.
This implementation seems kind of crumby because my options seem to be:
- allow google bot to crawl my images (which I don't want to do)
- use the nosnippet tag which blocks the preview, but ALSO snippets (which I don't want to do)
- Let the wonky previews appear which may adversely affect click throughs