Create game-like looking isometric view of the Tamedia main building and it's surrounding with a billboard on the roof that says 'Tamedia:TX'. I've included a mockup (mockup.jpg) that shows, how I imagine it (feel free to be wild on the interpretation of the mockup - it's really just an idea). The photo in the mockup should rely somehow on a 8bit-game-city aesthetics (as provided in the aesthetic suggestions).
The main building and it's surroundings should be recognizable (therefore some pictures of it), but some fictional airplanes, monsters, UFOs, superheroes and other higgeldi-piggeldi would be much appreciated - it should look like in a game.
This picture should be on the front of the T-Shirt where as on the back there should be just the Text 'Tamedia:TX 2015 Zürich, 25th of June 2015'.
Update: I've added some more aesthetic examples of cities, that I could imagine - so the T-Shirts look less childish.
Update 2: The part of the city can be much smaller than in my original mockup. Important is, that the main building is recognizable and that the river and the streets around resemble the real situation.