I'm mobile so I can't see the pictures but....in plazmic you can change the wall in the apps section if this is a theme your building. If its someone elses theme you can't change the app menu screen but if you ask the theme builder they might change it for you. I know I would for my themes.
Are you building this theme yourself or is this a theme you have downloaded?
The application wall has to be inserted into the theme buy the developer at the time of building it. So if this isn't yours (you built it) then you are out of luck, unless you can contact the developer and have them add it on for you.