The pace of work is very high and the work can be very demanding (it also depends how high you set the bar for yourself, but considering you're a creative you want to strive to make the best work possible).
You have to clock your hours to the minute, some people are okay with this (in the end you're working on paid projects, not on a hobby project), but others find it frustrating. It's a very efficient company, not some playful design studio.
Junior, medior & senior. It can take some time before you get a new title and quite some HR talks before you make the jump from junior to medior.