Board Thread:General Discussion/@comment-47881-20120918132608/@comment-5188108-20121031144330

I think there are different types of scan. Notice in the HoJ they have that drop down scanner head, which doesn't appear in the Cave or the Watchtower. Because the HoJ is a public place, they are probably more careful about IDing the users than inside their secret bases, or perhaps making a show for the tourists so no-one thinks there are invisible scanners all over the place. Similarly, in Misplaced, it makes sense that when the computer didn't recognise him the first time and Billy asked for another scan, the computer would use a more intensive (and visible) scan that normal.

TLDR: it depends on where the teleporter is and how intense the scan is.