This chair was designed for the Tugendhat House in Brno, Czechoslovakia. Much greater strength is achieved in this design, visually and physically, by the use of flat metal sections for the frame, and the flat ground level spacer.
The fact that the frame disappears behind the shallow upholstered elements, leaving the leg/arm lines the only visible support gives the chair a more cohesive form. The seat and back are firmly held in relation to one another, and relieved of any structural load. Like the Barcelona, the chair is almost entirely hand made, though far fewer operations are required.
The chairs in the bottom photo show the small arm pads that have been added to the design.