The RepresentationCondition of measurement asserts that a measurement must map RealWorld entities into numbers and empirical RealWorld relations into numerical relations in such a way that the RealWorld relations preserve and are preserved by the numerical relations.
In other words, your numerical model must always make sense in terms of the RealWorld model it is attempting to describe.
LOC satisfies the RepresentationCondition for physical program size but it doesn't for functional program size because you can have a poorly written program with more LOC but same or less functionality and vice versa.
The funny thing is that this concept arose to remind people that metrics should be actually related to reality. CommonSenseIsnt