If you're talking about modifying the L shaped desk sitting to the left of your sewing machine, it looks like it has a single drawer. Many years ago, I cut a hole in my husband's sturdy1960's era desk for my Kenmore. I placed the piece that I cut out down in the drawer and set my machine on top. It brought the machine bed flush with the surface. I don't remember if it needed a scrim or two. That machine had a drop-in bobbin, so I didn't have to remove the machine from the desk very often except for cleaning. Now I sew with a vintage Bernina 830 with vertical bobbin access below the bed of the machine. If I didn't want the inconvenience of pulling the machine out of the recess each time I needed to change the bobbin, I would have to remove the drawer completely. Then you would have the complexity, relative to the construction of the desk, of bracing a shelf below the desk surface.