GnuCash offers several options for viewing your registers. The default style is Basic Ledger mode, which displays only the summary of splits affecting the current account. This is the style that most closely resembles other popular personal financial packages.
You can choose a different register style by selecting View -> Style from the menu. The Auto-Split Ledger style expands the current transaction automatically. As you highlight a new transaction in the register, the transaction automatically expands to show all splits. The Transaction Journal style is more like an accounting journal, in which all splits are shown for all transactions.
All styles permit you to view your data in either single-line or double-line format. In the View -> Style menu item, check the box next to Double Line, and you will see your transaction line expand to two register lines.