I saw this at some site and wondering whether could this get you penalized or banned? There are other sites too that used 1 Big image beside the ads.
I don't think so, in what way is it misleading?? First there is not two images in front of each ad and secondly the image is very generic and the guy in the drawing doesn't have an pointing finger to the ads!
I know a friend who got banned with the same case as what you have here... the same location of the image and the Ads. I'd rather not take my chances as this will be a one time regret and better avoid the risks and learn from experiences.
The best is whenever you decide to put an image next to an ad, is to immediatly send a message to adsense asking to kindly review your page for compliance with adsense tos. Most of the time they'll say it's fine, because on forums we have a tendency to scare each others and to be more monarchist than the king.
Please do contact google and find out - im pretty sure they will say you cant have that image next to the ads. If however they do say you can - then cha ching - a hell of a lot more of us are going to up our CTR!