>> When I see pictures of food on a menu, I expect them to be real pictures of an example of the actual dish I'd get

> I don't get who would think that's a good idea.

It's super helpful to the customer, because it gives you a much better idea of what you're going to get. That's especially true with ethic food, where the descriptions use unfamiliar terms or a lot of meaning is lost in translation.

> Like if I order something because the picture shows that the dish has carrots or something and the dish you bring doesn't I'm going to complain.

Seriously, what's the problem with that?

Are you, for some strange reason, taking the perspective of a restaurant that wants to behave in a very customer-unfriendly way? Randomly dropping or substituting ingredients is not something a restaurant should be doing.