If you tick this option, then the listbox for this particular procedure will print with exactly the same vertical limits as in the window. This mean that if there are more records than those that fit in the listbox, they won't print.
If you don't tick this option, there is no vertical limit. This mean that if there are more records that you cannot see in the window, they will be printed on the report if your list is file-loaded. The template can print only what's loaded in the queue, so if you don't load the queue using the "file-loaded" option, only one page of records will be printed.
If your list is page-loaded (As it's always the case on legacy browses, unless you load the queue manually), then this option will have no effect at all.
When there are more records in the queue than fit in the window, the printed listbox will grow to accommodate them. If there are other controls below the listbox there will be overlapping, unless you activate the Move controls on expand text or list local option. In that case, all controls below the listbox will move down, and all the controls surrounding the list box will resize to fit the new size.