From such a perspective therapy per se does not exist. There is only
relating, by both parties, to self and other. Containment is a central
metaphor for understanding relating. The therapist's 'analytic model' of
choice is wholly interior. The more material that a therapist is able to
contain the less likely that he will unconciously 'project' it.  Conversely
he is more likely to discriminate or be sensitive to the patient's
unconcious material as other. This containment necessarily includes any
model that he might be using.

How does any of this relate back to the topic of dreaming? The notion that
a dream is "transmitted" to me makes some sense if I think of it in the
following way. Things are continuosly transmitted that we are varyingly
sensitive to conciously and unconciously. I think of a dream to be a wholly
intra-psychic phenomenon, but to the extent that transmissions were
received  unconciously it seems quite reasonable to understand them as
integral with dream material. The debate over whether or not they are
aspects of "ones' self" is itself a projection of our inner. Metaphysically
it seems that any image we 'contain' is an aspect of self, in that it
originates from our organic 'selves'. Psychologically any interpretation is
a reflection/projection of our inner. To argue the validity of which
psychological interpretation is real or true does not seem the issue. If
the dream's interpretation succeeds in having the patient contain more of
his own material appears to be the important question. Any unilateral
'belief' of the therapist in this respect (be it Jungian anima, Freudian
repression etc.) is nothing more than the failure of the therapist to
understand the inner origin of his idea (lack of concious containment).
This of course is likely to blur the therapist's sensitivity to the
patient's material and will contribute to countertransference.

Of course this doesn't answer the question psychologically. There may be
reasons to argue the usefulness of identifying some  material as belonging
to other. With respect to containment an individual is not able to just
assimilate whatever is unconcious to him. The varying capacity for
containment is what defines us. Whether an inability of the therapist to
make the personal connection of dream material, or a therapy model that
ascribes generic material to a collective origin, or a 'sense' that the
material can't be assimilated yet,etc., the therapist may decide to
interpret it as belonging to other.

In a rather circular fashion here it is the nature of the therapist's
containment that will dictate both how he interprets as well as how
sensitive he is to the evolution of the patient's.