How is this possible (Animated Backgrounds?)

I was looking at games i could join, and i came across this: <a href="https://app.roll20.net/lfg/listing/11565/descent-r" rel="nofollow">https://app.roll20.net/lfg/listing/11565/descent-r</a>... How does one enable that? Eddit: Here another one <a href="https://app.roll20.net/lfg/listing/10997/the-fall-of-wintergrove" rel="nofollow">https://app.roll20.net/lfg/listing/10997/the-fall-of-wintergrove</a>

Custom campaign backgrounds are a feature for supporters and mentors, but mentors also get the option of motion backgrounds. You view the different benefits of the levels of supporter on our subscription page . The custom backgrounds are noted under the "Plus" section.

My Campaigns---&gt; Choose a Campaign---&gt; View Details---&gt; Campaign Settings

As a supporter, if you'd like to enable the non-motion custom background for your own campaigns, just go to the campaigns detail of the campaign and click on "campaign settings" which can be found on the left side in the listing of options. It will take you to a page that will have "Campaign background image" as one of the sections and you can choose one there. EDIT: Stephen beat me to it! :)

Since we are on the topic, will more backgrounds be made available over time, or will (are?) we be able to upload our own? Sorry, but "starry night" feels just a bit inadequate for my swashbuckling gothic horror game. ;)