Visual reps, IMO, are the hardest /unfairest forms of asesment out there. If you dont represent something that is ideal to the marker, then you can really be in hot water.
I'm not very sure what you're trying to ask, so post up your specific assesment question (ie. what kind of institution) then other can give you ideas
I'll give some ideas anyway:
+Define what an insitution is
+Ask people/look on the internet about different peoples experiences after coming out of one and how they define what an institution is
+Emotions can be represent by colours
+Religious images represent good evil
+Everything IMO, especially about life, is a game
