Meaning that the author is maybe not very good at their craft, but inadvertently created a work with a lot more meaning than they intended, or they accidentally did something quite clever that they didn’t mean to. Or maybe a work which is good in its own right but there’s a particular “unofficial” interpretation which makes it so much better.

Obviously a bit of this question involves knowing authorial intentions, but in a lot of instances authors have been able to state that they did or didn’t intend a particular interpretation.