Hello Goat,
My maple is a broom. So-called because when bare it looks like an upside down broom, the kind made from bundled together twigs. There is no before and after in the sense I think you mean. It always was a broom and it will always be a broom (well, its dead now but you get the idea).
Formal upright is completely different. It is characterised by a straight vertical trunk with horizontally placed branches, like the trees in the gallery that Bri linked to.
Take a little time to browse the gallery, you will find plenty of examples of both broom and formal upright.
Hope this helps to sort out any confusion
Regards,
Chris.