As Scotty is guiding a piece in from the top and sees Gillian down on the ground, you can see the thick packing crate the factory built around the plexiglass.
When Gillian (and we) look up, Scotty is visable from the waist up, the upper part of his body is above the clocking 'field', the lower part inside the field. Could Scotty, because he was so close see inside the field. Could Scotty see his own feet, the birds hull amd the opening he was guiding the crate in to . Or was he doing it all by 'feel'.
T'Girl