I would say the quality is usually too poor to ship, but good enough that it can slip through unnoticed.

It's like a web developer using their own photo as a placeholder for the CEO on an "About Us" page: seems like a fun little in-joke, until it accidentally ships and you get an angry phone call from your boss's boss. It's better to do the boring thing and play it save by using a big red cross with "REPLACE ME" on it so you'll definitely catch it during the final review.