There is a full dust board between the drawers and the display section of this cabinet, and it is there for a reason most people never think about.
A drawer is a piston. Push it in and the air inside the carcass has to go somewhere; pull it out and air is drawn back in. That air carries dust with it, every single time. In an ordinary chest that is harmless - the dust ends up in another drawer.
In a glazed cabinet it is not harmless. If the drawer section is open to the display above, then every use of a drawer breathes dust up into the space where the glass and porcelain are, and it settles on the shelves. The owner ends up wondering why a sealed cabinet needs cleaning so often.
So the display compartment is closed off with a solid dust board across the full depth and width, fitted into grooves in the carcass sides rather than simply screwed underneath, so there is no gap at the edges for air to travel through.
It costs a board and an afternoon. It is the difference between wiping the shelves twice a year and wiping them every month.