LeWitt can be claimed for either conceptual art or minimalism, but his works rendered from verbal descriptions are more conceptual. They can be made even more conceptual by removing words, by using mathematical notation. This is a line of resistance to the lit-crit land-grab of Art Theory. Art may be a language (an insight at least as old as Ruskin) but it also has a mathematical basis that goes back to the earliest geometric cave art and was hardly reduced by perspective or by modernist abstraction.
The LeWitt pieces are in part about what the verbal and mathematical descriptions cannot capture. This is a kind of aesthetic platonism by counterexample, which is a very Rob thing to do).
Vermeer is resistant to language as well, but he is also resistant to simple mathematical encoding, so a lot more would be lost in a mathematical description. Taking this loss for the moment, the poses of the people in Vermeer’s paintings can be expressed as dance notation. This can then be further abstracted (Gödel Numbering, Saville Colouring, etc.). The LeWitts can become Vermeers by converting them to dance notation then rendering that. The Vermeers can become LeWitts more easily.
Somewhere they will meet.