You can save and load snapshots to files on your computer, you can copy items from a snapshot to a library, and you can edit the first seven items in the snapshot (see Editable Items for more on that). The snapshot is basically your interface to the TX81Z within the TX81Z Programmer.
One thing you can't do with snapshots is rearrange the items within them. You have to copy the items to a library first with one of the Add To Lib buttons and then copy them back into the snapshot where you want them with the Copy Items From Lib button.