I've seen this same technique on two blogs I frequent, but I don't want to mention the URLs as I don't want them to be banned... Assume I have a blog with a 500 pixel wide main column, and at the head or foot of each post I want to add a 336 x 280 block. So, I decide to put a 164 x 280 image on the left, and the AdSense block on the right. Is this allowed? One blog has an image related to the theme of the blog, the other has one related to the blog name, which is completely unconnected with the theme of the blog. My gut feel is that the related image is a no-no, but the unrelated one is perhaps OK.
Can't you take a picture? or you can refer below official info What do unacceptable implementations look like? Here are some examples that wouldn't comply with our policies.
I wouldn't suggest putting images next to your AdSense code as being a good idea - as far as I know it's against their TOS. I could be wrong though!
If you try and make any image look like its associated with adsense and have it too close then its against their TOS.