Your account has been giving extended rights. It is also being monitored. Do not fuck with anything besides what you see in this tutorial or they will be taken away.
Step 1. Click unite gallery from the left menu.
Step 2. Select edit images from the gallery you wish to add to.
Step 3. Click add images, upload the images and click insert.
I do realize there is a 20 image limit, when it's reached I will upgrade to the pro version.