Objects can be displayed in pimcore with custom icons. This makes objects distinguish themselves visually based on the class they are based on.
In the object tree the user can see on the first sight what an object should represent. The example below shows how custom icons are assigned to a class (Extras/Object/Classes) and how they are displayed in the object tree. It is easy for the user to see immediately which objects are of the type "football".
Icons that come along with pimcore by default can be found in PIMCORE_DOCUMENT_ROOT/pimcore/static/img/icon.