Aesthetic Impact
In the beginning of a session, your mind is "winking about the site", trying to get its bearings. This is an unavoidable process which happens to viewers and natural psychics, alike. During this time, any effort to make sense of the target is only going to lead you astray. But, if you wait, collect impressions, and let the mind get its bearings, you will suddenly realize that the mind places you into a sort of mini virtual reality, where the target feels like it is around you, in front of you, above you, etc. In other words, you begin to have a spatial relationship to the things at the site. This is the point at which your mind has gotten its bearings, and in effect, says, "OK Now I can relate to this place."
Until that happens, you should just allow the mind to "wink about the site" and not try to make too much sense of the perceptions. After the Aesthetic impact happens, you will begin to get more coherent groupings of perceptions, as your mind examines first on thing and then another at the target site. Also, at this time, it will be very natural for you to start drawing sketches of the site. This is a desired reaction, and is to be encouraged.
See also, "Winking about the site"