looking at this screenshot of blackberry, http://www.cellphones.ca/news/upload/2009/01/blackberryvoicemail2.jpg http://www.cellphones.ca/news/upload/2009/01/bla

looking at this screenshot of blackberry, http://www.cellphones.ca/news/upload/2009/01/blackberryvoicemail2.jpg http://www.cellphones.ca/news/upload/2009/01/blackberryvoice..., it also has variable height along with variable width. what is the benefit of variable height vs uniform height?