Because the data source of the nested Repeater you added to the Default.aspx page is a collection of Review instances, it has been made strongly typed by setting its ItemType and using its Item property as opposed to using Eval. As you learned previously, this makes it easier to write code and catch errors earlier.
The nested Repeater looks a bit like the code for the AllByGenre.aspx page that has a Repeater that contains a BulletedList control. Just as in that page, the nested Repeater gets its data from the outer Repeater with the DataSource attribute: