I'm designing a landing page for my web app, and some of the options I have include pictures that intend to approximately mimic the app's user interface and give the customer an idea of what it looks like. It features some primitive data forms, a couple charts, a logo, etc.
My question is: would it hurt if those images were stylistically different from the actual interface? I'm tempted to say that it's a bad practice, because seeing the interface that's totally unlike the landing page would probably make the user feel cheated. Is this a justified concern, or is such a difference a normal thing to have?