What's the difference between RGB design of NFTs and common NFT approach?
In general, the way DRM (Digital Rights management) system works today is very far from individual/author/owner-centric, leading to appearance of huge industry of distributors and labels and impossibility to buy into ownership of some certain content.
So the assumption is, that removing the ability to prevent copyright technically (current DRM) and use instead economical incentives is much more sustainable and will lead to the healthier ecosystem. That is what can be expected from the RGB NTF design.
So, the change with RGB (in legal terms) is:
when content creator sells his content, he (1) does that directly to the buyer and (2) he sells the right to copy (i.e. "copyright”) with it (which is the actual ownership over a piece of content) - and he can do that multiple times. RGB provides distribution channel (LN+Bifrost), decentralized storage (Bifrost+Storm), payment (BTC, lBTC or RGB stablecoins like USDT) and protection of the content from being accessed by non-buyers (client-side-validation with encryption and confidentiality) for that.
when content owner sells content, he has two options: (1) sell access to the content, for smaller money than when the content is sold, so he sells “usage rights”, and the new content user will be able to use the content/copy multiple times, but will have a challenge of selling it (still being able to distribute it for free) and (2) pass the ownership rights further, the same way the content creator did.
This indeed does not provide copy protection at technical level. But what it does, it provides free public access protection at technical level (until one of the content users will publish it for free).
That is weaker publisher guarantees comparing to DRM, but stronger comparing to any other NFT or alternative out there (and the same strong guarantees as with software licenses back in old days).
At the end of the day, arguably, there is a probability that if we take game theory & economy into account (and not only technical means) that will still give more profit to the content producers because we remove intermediaries (lables/distributors) taking 90% of profitability from the equation + provide economic incentives to pay to owners, and not cheating content users.