Google has introduced a new type of image/media ads in which the users have to click twice to go through it, and in other way they have to click twice to make you money.
Well, I'm sure that you'll make money because your visitors will enjoy while going through this expandable Rich Media Ad. This ad is currently available for North American and European Publishers only.
How do these expandable ads interact with users?
The ad will be presented normally to the users, but when they click on it, the add would then expands to some size not more than double. Hey! Don't worry about your page's design layout, it will not get modified. Reference is given in Adsense Blog about it:
Ads will expand only after a user clicks and interacts with the ad. Mouseovers or rollovers won't trigger the ad, in order to prevent accidental expansions.
An expandable ad won't expand more than double its width or height.
Once expanded, the ad will appear as a layer over the page content so that your content will not be modified or shifted in any way.
The user may close the expanded panel at any time.
All expandable ads must comply with our standard AdWords image ad policies.
So, as mentioned in the point “Once expanded, the ad will appear as a layer over the page content so that your content will not be modified or shifted in any way.” I think this point has cleared the above query.
How to place expandable ads?
If you have placed Image only ads on your site and you're a North American or European Publisher, then Google will automatically start serving Expandable Ads to your visitors.