Whenever you have selected only one picture, a preview, its name and its weight (if enabled) are shown. There is either the picture name or the picture preview selected, which is shown by an insertion point or a hilite in your hilite color in case of the name, or a thicker border in your hilite color around the preview. You can switch selection by clicking into the name or preview, or by pressing the Tab key.
You can simply change the picture name (shown below the Import button) by the usual means, if the name is selected. To accept the change, press the Return or Enter key or simply select an other picture. If you accidentally changed the name, you can undo the change by selecting Undo from the Edit menu. Also, the Cut, Copy, Paste and Clear items from the Edit menu will function normally.
To change the weight, use the scrollbar below the name. If the picture is not yet enable, first press the On button.