Another thing that i always wanted to know if the art submitted by the people who get the prizes, do those become the propriety of Roobet.com ?
I've won design contests before and the contest results are used by the contest owner for the logo of the platform, so I think any art from the contest win will be claimed by Roobet. The design results uploaded must be unique and attractive according to the rules above, professional designers usually will not use the same design for other contests so that the results of the art contest will absolutely belong to the contest owner, the prizes given are equivalent to your efforts to win this art contest.
As far as I know they are not getting the original file of the art and I didn’t see they use any art for their marketing purposes, this is solely for the purpose of contest. They are actually buying the physical art as they post an offer before, maybe they are planning to have a museum for the Roobet art.

It all depends on the purpose of the contest, generally any design results from the contest winner will be submitted to the contest owner, but this contest is not directly related to the design for the logo or design related to the main points of the platform, this contest is to celebrate the amazing collaboration of Snoop Dog x Roobet , so the results of the contest will be added in the collection and used for advertising or other necessary parts.