Something of the subject is found in the object

1. Can anybody understand what actually "the subject is depleted to the extend that something of the subject is found in the object" means?

2. Does "subject as an isolate" mean "subject as an isolated phenomenon"?

Context:

The central thesis of Dr Winnicott's paper is the proposition that the use of an object constitutes a more advanced and sophisticated stage of development than does relating to an object. It is a paper wich continues the author's long-standing interest in the individual's capacity to find and then use the "external" world with its own independence and autonomy. Object-relating, to Winnicott, implies cathectic changes investing the object with meaning; and via projection and identification the subject is depleted to the extend that something of the subject is found in the object. It can be described in terms of the subject as an isolate. If the object is to be used, it must be part of a shared reality and not "a bundle of projections". In exploring the use of an object, the analyst must therefore concern himself with the nature of the object as a reality and not as a projection. According to Winnicott, object usage can be described only in terms of the object's independent existence. The clinical paradigm would refer "relating" to a baby who in fact is feeding at the breast, but psychically is feeding on the projected self; whereas, "usage" would have the baby feeding on (using) milk from a woman's breast (http://pepsic.bvsalud.org/scielo.php?script=sci_arttext&pid=S1517-24302005000200008).