**UPDATE: Starting from 6 October 2016, all JotForms are now secured with SSL without any limitations!
Open your form in edit mode from the My Forms page, and then:
1. From the Form Elements menu, click on Image to access Image wizard.
2. In the Image Properties, select General tab, then select Comodo Secure Seal under My Images tab within Choose a File option.
NOTE: The Security Seal will show up, only on forms which make use of SSL (start with https://…)
An example form is here: https://form.jotformpro.com/71976908405972