There can be communion between two persons. It asks deep involvement of both. We communicate verbally with each other to understand our points of view at the same level. Sometimes we succeed in mutual understanding and sometimes we fail.
If both the persons know the same language, it can be possible, but to communicate with each other properly, it is important for both to be urgent and have the capacity to listen and to act at the same level.
If one is looking here and there and the other is talking, it is difficult for both to understand at the same time because one is serious in this act and the other is not, so the communication ceases.
There is a communication which is not verbal, which comes about when both are serious and intense at the same level. This is the point where non-verbal communication counts. In this case, both persons can deliver equally in their words and in their actions.
It is also possible that both persons could sit in silence but with mutual understanding.