When you look at the Account register (the list of your transactions), by default you see the amount and transaction description. However, MoneyWiz allows you to freely change what you see using Transaction layout settings. To begin, go to Settings > Transaction layout.
The order of fields in that window not only affects their order when you go to create a new transaction but also what's displayed on the transaction list. The first text-based item (not necessarily on the very top of the list, just above all other text-based items) will be the thing you see for each transaction without expanding to see more details. Feel free to experiment with this setting until you find the configuration you like and click here to learn more about transaction layout in general.