Simply go to the 'My ads' tab in the new interface and under 'Content,' choose the 'Ad units' page. Using the checkboxes, select the ad units you’d like to edit, or simply select the checkbox at the top of the list to select all of your ad units. Using the 'Actions' dropdown, select 'Edit ad type.' Choose 'Text & image/rich media ads' and then click 'apply ad type.' Now any ad units that can be opted into both text and image will have this set as their ad type.
We recommend opting your ad units into both text and image to increase auction pressure, ensuring you will get the highest RPM possible. Keep in mind that some units such as link units and certain ad sizes cannot contain image ads, so you will not be able to modify these ad types.
Try it now! Navigate to the new interface and click on the
My ads tab, and then 'Content,' followed by 'Ad units.'
Posted by Alex Benton - AdSense Engineer