Positioning your characters at the edge of the frame is often used to convey a sense of isolation or evasiveness. It’s an unconventional style of framing that ignores rule of thirds and conventional rules about look room, often only showing part of a character’s face.
This technique is used to grate effect in the first episode of Mr Robot as we are introduced to the life a brilliant but paranoid hacker who believes that he’s being followed.
In The Silence of the Lambs (1991), director Jonathan Demme sandiwches Clarice Starling (Jodie Foster) against the edge of the frame, peering around the corner of a brick wall, when she receives an unsettling telephone call from Hannibal Lecter (Anthony Hopkins).
If you want to convey a sense of evasiveness or isolation, consider positioning your character right on the edge of the frame but keep in mind that this style of shot is highly unconventional.