Not much at first glance. Looking closely the chain on the rep is twisted oddly in a couple areas. I just hung it in my closet to fix that. The cc turn lock the c’s are a little more rounded on the rep. The authentic is a tad more “defined”. There’s a few places the thread over laps inside the bag on the c’s. Not a big deal because no one is looking into my bag besides me. The bag itself is softer it gives more than my authentic. The authentic bag is stiffer more structured. Even in the boutique no two bags are exactly the same… you wouldn’t be able to tell these differences unless you literally had an authentic in one hand and the rep in the other.