(By Hedvig Skirgård): "This question concerns predicative possession, i.e. clauses that express an ownership relation between a possessor and possessum. This feature is concerned with clauses where the possessum is the subject of an existential/locative predicate and the possessor is in an oblique form marked by an element meaning ‘at/in/on’ (e.g. the car is on me to mean ‘I have a car.’ or ‘The car is mine.’). The possessor-NP need not be overtly marked for location, it can be expressed in the verb itself, e.g. with a locative extension. It is necessary for the construction that the possessor is not the subject. ❡
This type of predicative possession construction is known as the ‘locational possessive’ in the work of Stassen (2001, 2013)."