Knowing Imagination

An interesting thing often happens when we do imagery as a group. After engaging in an imagery session done in silence in the group setting, it is not uncommon for the individuals in the group to discover during the following sharing that other members of the group have had imagery that is similar to each other in some way. This has happened in groups that are meeting for the first time and groups that have met together before. It seems to happen more frequently for people who have experience in the process, not so much for first time practitioners. For groups that have met over a long period of time with experienced practitioners the frequency and depth of the similarity increases.
I am not sure why this is so, but it is clear that it happens, to the delight and amazement of those involved. My guess is that since the domain of the imagination is not limited to the limitations of space and time that we are accustomed to, the supportive and safe environment of the group practice allows the practitioner to both relax their boundaries and to be aware of subtle connections between people that may be present all the time but are not ordinarily perceived. It is always exciting to be come aware of those kind of connections.
Does anyone have any other ideas how or why this might happen? Any similar experiences with the imagination to share?