@Andrea1160
Andrea, it's a matter of perception!
Almost all guests would consider an 'indoor fireplace' to be something that burns wood. When they turn up and find that it is simply an electric radiant heater, they would feel the amenity had been misrepresented, and it could back-fire on you.
Under amenities list it as electric heating, show photos of it and describe it as a very effective wood fireplace look alike. That way you have been accurate and would not be seen as attempting to deceive!
Cheers........Rob