A cheaper, poor-quality copy of something better or more famous.
The term stems from the fact that, in grade school, most kids would have the pricier, top-quality Crayola Crayons, while the unfortunate few students would be stuck with the cheaper, crappy Rose Art Crayons which nobody wanted.
Hostess snacks are the Rose Art Version of Little Debbie snacks.
In IT when management cannot get anything done because they are unable to decide between the current version of software, and the promised "next version".
It has variety of meanings, but it is also used as a mark of being a Swiftie on The Internet. Taylor Swift herself said it means that it is owned by Taylor Swift. It is kind of an inside joke that isn't one actually.