The awliya get to see many things, some of them can be classified as less important than others. They get to see for example the seven skies and its angels, and also the whole world in front of them, where they can see for example where a loved one might be if they are travelling somewhere else, just like when sayidina Umar while in Madina observed another Sahabi in Syria who were in a battle and were facing difficulties, and also more importantly the Awliya can see paradise and hell, and their details and peoples from their hearts. The spirit of a human being is far bigger than this earth. About the secret, it is witnessing Allah swt, seeing Him in His power, beauty and glory and seeing Him in His Essence and His Attributes, people are closer to Allah in proportion to what they have of this secret, we all have a portion of this secret when we follow the Prophet sallahu aliye wasalam sincerely and worship Allah seeking His face, as with every step we take towards Allah, Allah comes to us two folds, and those that are the closest to the Prophet sallahu aliye wasalam, inward and outward, will get to see Allah even more clearer, and will experience the beauty of His face, and coolness of His glory in more excellence. The Awliya inherit through their teachers these divine witnessing and presence, who in turn from their chain of teachers inherited from the Prophet sallahu aliye wasalam, and just as when being with a perfume seller, some of the perfume falls on the person, likewise those around the awliya get incensed with the secrets they hold, and which appears in those individuals as increase in eman, and motivation of seeking Allah swt with doing more good actions.