I have watched many videos on the internet on closing nights. Most of them have speeches at the end. Some of them reprise some roles at the end. They add in special things the actors think of. Most of the fun stuff that happens in the show is it becomes longer because everyone cheers and claps after every funny moment and song. The difference between a last show for an actor, they might make a difference to make the show memorable. An example would be kristin chenoweth adding something to popular when she says "I wrote a book."