You might say, wow, the pizza looks really good.

Here, the locutionary act is simply expressing admiration for the pizza.

You are literally stating the pizza looks appetizing.

It's just the surface meaning of the words.

The locutionary act here is actually a hint or a request.

You are not just commenting on the appearance of the pizza.

You are subtly trying to get your friend to offer you a slice.

The intention behind the statement is to prompt the friend to share, even though it's not explicitly stated.

The prolocutionary act is the effect this statement has on the pizza's owner.

Maybe your friend will feel guilty and say, okay, fine, you can have a slice.

Or maybe they left and say, nice try, but this one is all mine.

The effect on the listener, whether they decide to share the pizza or not, is prolocutionary act.

The outcome depends on how the pizza owner interprets it.