True meditation never happens "objectively".  We cannot, so to speak, look-in on our own contemplative meditation.  Meditation first begins there where we are "met", "touched" and have "entered into the picture" ourselves.

This is true for every meditation.  With an icon meditation we can practice intentionally letting ourselves be drawn into what we are looking at.  We can practice this with other materials also (for example, biblical stories).

What do we mean when we say, "let ourselves be drawn in"?  When I meditated on the icon, Michael The Archangel, also painted by Rublev, I became aware that this was a passive process.  The angel looks down reflectively.  I experienced how the angel inwardly viewed the people to whom the message was brought.  All at once I felt myself as seen by the angel and I experienced how the glance rested upon me.  I lingered.
So we have to allow ourselves a place in the icon and sense where we are or would like to be and linger there.  In many icons we can identify with one of the persons presented ("you are the One").  With other icons we find our place between, in front of or next to the persons depicted.

- Andrei Rublev - The  Trinity  (Meditation on picture)
Wait for a place in the icon to be "assigned" to you and let yourself be drawn into it...