For those wondering, a codpiece is a bit of medieval men's fashion, a sort of pouch to hold and emphasize the genitals (from the older English "cod" = scrotum) — which doesn't make much sense here.
What Aria is holding there, all censored, is presumably actually a sort of dildo called a "softie": a soft silicone penis and testicles, flaccid, marketed for "packing", wearing inside the pants to feel like you've got that equipment.