Stylesheets are similar to queries that select specific pieces of data from a relational database. The ESRI stylesheet does not show all metadata elements stored in the metadata. It is designed to show the most commonly used information and properties of your data, including the mandatory FGDC elements.
Similarly, the FGDC stylesheet shows all FGDC metadata elements stored in the metadata. It does not show metadata elements defined by ESRI that contain properties of the item such as the data type of an attribute, properties of a relationship class, or connectivity rules for a geometric network.