The edge implies there is a wall but makes line of sight and access to the space easy for sitting players.
Dm scotty floors.
My vids help you make cheap and easy terrain props and set pieces for your dnd and table top games.
My 2 5d next where the walls are still low to the table but modular making it easier to produce any layout you wish and my final and current iteration dm scotty s tilescapes where i use more 3d elements but my tiles have no walls.