Google Rules to Follow:
Ads must take up the entire space of the image size you've chosen, and they can't appear sideways or upside down. Ads can't be segmented, contain multiple copies of itself within the ad, or appear to be more than one ad. Google also doesn't allow ads that expand beyond the frame or otherwise encroach on the website.
Note that in each image ad, we include a small informational graphic overlay (top right). We will not resize your image to accommodate this element. Your ad should always be submitted in the full original format size and take this overlay element into account. If the ad you submit is resized in advance, there may be extra white space visible when your ad is displayed. You can preview how your ad will appear with this overlay during the ad creation process when creating a standard image ad or a template image ad in the Ad gallery.
Relevance and quality
Image ads must be relevant to the advertised site. Ad images must be clear and recognizable, with legible text. We don't allow unclear, blurry, or unrecognizable images to be used in ads.
Strobing and flashing
Google doesn't allow strobing, flashing backgrounds, or otherwise distracting ads.
Mimicking site content, news articles, or text ads
Google doesn't allow ads that mimic publisher content or layout, or news articles and features. Ads may also not contain screenshots of Google AdWords text ads or otherwise simulate an AdWords text ad in any way.