Select the polygons highlighted in the image above. Bevel them using these settings: Bevel Type=By Polygon; Height=0.25; Outline Amount=0. Hit Apply. Bevel Type=By Polygon; Height=0; Outline Amount=0.4. Hit Apply. Bevel Type=By Polygon; Height=0.2; Outline Amount=0.2. Hit OK.
Select the 2 middle-top polygons and enable Soft Selection (Falloff=16; Pinch=0; Bubble=0), uncheck Affect Backfacing and drag them down a little.
Exit the Edit Geometry Mode, go to Modifiers List and add Mesh Smooth with the 2 Iterations. In the Left Viewport Shift+Drag to make a copy of the pillow and then rotate, move and scale it until it fits the back of the chair. The Barcelona chair is done!
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