I wouldn't necessarily say it was "artistic" because to me that implies that the effect was contrived or deliberate in some way. "An attractive muss" might be better.
If you are interested in where the expression comes from, I believe it is probably from a Robert Herrick poem called "Delight in Disorder" (You can read it here). Herrick generally is well worth a read, actually. It's a poem I've always loved, and given that the quote in your post is from Dickens, I would be very surprised if it wasn't meant as an allusion to it.
That's actually partly why I don't like your interpretation of it as "artistic muss"; the whole point of the poem is that the "sweet disorder" is not artistic or contrived, as the poet points out in the final couplet.
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