Describe in detail what you saw.
Some elements that might be important: Visuals such as colors, textures, geometric shapes, directions of travel (where movement is concerned), levels (high, low, medium), scale (very large to very small), physical relationships between/among people or groups of people, physical relationships between/among objects. Is the work emotional, intellectual, spiritual, political, religious, cultural, etc?
In the case of architecture, identify the function of the building: theater, courthouse, home, apartment, office building, school, cathedral, mosque, technically specific for a particular function (such as an airport), etc. Identify the materials it is made of: concrete block, marble, wood, glass, mud, steel, brick, combinations of any of the previous plus other materials as appropriate. Identify the style of the building: classical, baroque, modernist, primitive, Islamic? Is the building well designed for its intended use? What makes this so or not so? In the case of an architectural exhibition, describe the theme or idea for the show. How was this communicated? Photos, models, descriptions, examples of materials, etc.
*If you choose to write about architecture, you must visit the building in person. Take a selfie of yourself at the building to prove that you were there. Email the selfie to the instructor or imbed it into the paper. Virtual tours of buildings are not acceptable. Since many buildings may be closed or inaccessible due to the current pandemic, you may wish to choose a different topic.