if it doesnt work u can always make it snappy like , instant show boxart and with delay add video snap, if no snap it will just stay with picture.But yes it should always put [emulator name] as default pic, its doing the same for my theme in case of missing background fanart
define surface then just add fadeart
local surface = fe.add_surface( 500, 500 );
local point = FadeArt("cartart", 0, 0, 500, 500, surface );
point.trigger = Transition.EndNavigation;
point.preserve_aspect_ratio = true;
surface.set_pos( flx*0.050, fly*0.200, flw*0.200, flh*0.250 );