Hi,
In case of a “polaroid” layout results without images are removed from the live results list. For vertical/horizontal/isotopic layout a container image is used by default instead. This should not affect the results on the actual wordpress results page though.
The results page should look exactly the same when the plugin is enabled/disabled, only the actual results should be different, when searching through the Ajax Search Pro search bar. I assume you are reffering to the results page on our demo site, this one. Our theme results page is coded this way, to display results like boxes with image and titles. It is a custom coded theme based on the underscores base theme.
The results template is not something plugins can change reliable (yet). WordPress is evolving very quickly though, so it is only a matter of time we can add a customizable results page layout. For now some page builders can do that, but I usually recommend customizing the archive page layouts via the theme options to avoid any conflicts.