Site Seals are static or dynamic images that can be implemented on websites secured by an SSL Certificate; they show your customers that the site is validated and verified by an appropriate Certificate Authority and transmission of data through the website is processed through secured connection.
A Dynamic Site Seal will allow you to have it appearing as a pop-up on your website. For OV/EV certificates Site Seals are dynamic by default and will include your company information.
Please check the instructions for the Site Seal installation following the related article.