Pros
The clients massive budgets allow for cool and creative things to be done.
Cons
As an intern you don't really "learn" anything. You basically do all of the things the employees are supposed to do, but don't want to do, so they tell you to do it. The owner comes up with an idea and just expects it to get done, which causes a lot of stress/tension at the office. Actual employees are overworked and underpaid and constantly complain about owner, making the office a toxic work environment. Interns are unpaid and are used more as "slave labor". You perform personal assistant tasks for the owner more than anything.