If I make art, I would like to get compensated by it. However, under market capitalism, my art has to sell well to make money, which means that I cannot make art out of pure volition, but have to adhere to what consumers like, which may not be in line with what I like. Plus, market capitalism/SnD opens up a whole other can of worms about copyright, piracy, and morality. With an LToV-based system for compensating for art, I will get paid based on how much I worked, rather than if consumers like it or not. In other words, I can allow people to copy and redistribute/remix it without worrying about a loss of customers. To quote George Lucas “[In the USA], you have to adhere to a very narrow line of commercialism”.
Socially necessary in terms of manual labour pretty much means the average time taken to complete a labour. If the industry standard is that it takes 10 hours to make a coat but you are newbie at it and take 40 hours to make coat, your coat does not have not have more value because you had to invest more time into it. It is used to avoid debunked pitfalls like the mud pie argument.
As art is something which is not mass produced and inturn unique, is it more valuable according to LTV or is it outside the scope of LTV?
For professional artist, deadlines mostly. This don’t change in socialism.