Quoted from ForceFlow:There's a scrap of arwork in one corner near the right outlane.
Judging by the condition of the artwork between the outline and shooter lane (which is peeling and flaking), I'm guessing the playfield got damp and the artwork started peeling off. I've seen that happen on some playfields before.
I'm guessing someone simply removed what had peeled off. Hence why the artwork on the inserts is still there.
It’s more than just the outlane.
Look inbetween the pop bumpers and pretty much the rest of the top of the playfield.