The proximity to the sun and its thin Carbone dioxide atmosphere is one of the reasons for why the planet looks this way. It makes little difference if people know a lot about Mars or if they are simply fascinated by its alien looks, as they are guaranteed to find joy in displaying Mars posters.
Don't be surprised if your guests will immediately ask you about aliens after spending a few moments admiring your Mars paintings. On a more serious note, the passion for celestial objects in general and planets in particular is very likely to have an unintended consequence. Since the assembly of posters is not limited to Mars but features virtually all planets in the solar system and various other galaxies, it is very likely to result in a breathtaking collection.