When I search for something on Google (say, "spaghetti"), I noticed that some results feature a thumbnail (presumably a featured image) next to the post. Other results, like mine, are text/link only. Is there something I can do on a WordPress.com blog to "tell" Google to pick up a certain image or thumbnail to display alongside the specific post's link when it shows up in search results?
PS: If it helps, I am not referring to the Google+ Authorship thumbnails, but rather the attractive, descriptive images that would entice a searcher to click on one link as opposed to another.
PPS: I completely understand if this would require a customized piece of code that could only be input on a WordPress.org site. Just wanted to cover all the bases before I write it off as something I just can't do right now.
Thank you in advance!
The blog I need help with is nomnomcat.com.