These pieces are for the Iconic Arcade base unit without any cabinet.
They help protect the cables or microSD card from being directly hanging and exposed, which are vulnerable to damage, especially if the unit gets moved around.

(Extra notes)
-The cable plate of the unit does need disassembly before the cable piece can be used.
-The microSD card slot cover is just meant to be taped since I didn't want to drill holes into my unit for it.
-There's a higher chance the microSD card cover can be knocked left/right rather than up/down so the sides are kept open on purpose to prevent damage.