I don't know exactly what you referring to but if you place pictures and ads properly it is OK with adsence.
by using HTML <img> tags. However, there must be a border between the images and ads, or a border around the images, or enough space between the images and ads (it's probably a good idea to ask the adsense team if the placement of images you make is ok). The images must not be inappropriate and shouldn't be designed to draw attention to the ads. Search the adsense forums here (using the advanced search) and you'll find a lot of useful threads on images alongside adsense ads. Good luck.
You can accomplish this via tables in basic HTML. Make a row (<tr>) and make two columns (<td>). The left column (<td>) put an image, the right column (<td>) put the ad code. Make the borders invisible (border="0"). Hope that helps!
I think you may be able to float the adsense ad over the image using style sheets or something, but I am not 100% sure and it is not something that I would do anyway.
I agree that it's probably not a good idea to place AdSense ads over an image. There are probably clever ways to make this strategy conform to the ToS, but it's definitely a grey area, and could cause problems down the road. Sam
If you did decide to do it then I would make sure the image is faded rather alot just so that it doesn't blend with the ads to much. But as I previously said it is something that I wouldn't do.