Inside Twitter's first-ever company retreat: Jack Dorsey's parents posed for selfies, Elon Musk was a no-show, and employees meditated with the billionaire founder

• Jack Dorsey once led a Twitter company retreat to boost employee morale and set a vision for the company.
• The 3-day event featured strange wellness routines, dance parties, and a special message from no-show guest Elon Musk. 
• The following is an excerpt from "Battle for the Bird," a new book by journalist Kurt Wagner. 

Jack Dorsey sat on the floor with his legs crossed and his back straight, silently meditating on a stage inside one of San Francisco's largest convention halls.