Working on a small department, you will spend a lot of time either alone, or dealing with customer requests. There really aught to be at least one person to supervise the department at all times and that can leave you with a queue of customers and furniture left to build. During quiet periods, this does give you a lot of freedom on the department, but can also be terminally boring.
The hours available can be very long, 10-12hour shifts being common. There is a lot of flexibility when needed though, such as catering for people with children at school leaving at a specific time, or students working holidays. Breaks are enforced however, if you don't take an hour for your lunch or the full short-break entitlement its expected you'll leave early or take longer next time.
There is no real opportunity for advancement. Departments take little managing, and managers will often train co-workers on systems such as stock management (really due for an update guys, lets have a GUI at least!) and paper reporting, but no real pay benefits are given for this management work.
Ever found yourself lost in an IKEA store? I totally understand. The store layout at Leeds was particularly odd being a prototype single-storey store. So many customers would ask for help after going around in a circle three times due to the path taking a right-turn at a blank wall, right next to a short-cut backwards. The external-warehouse this layout necessitated also confused customers, who would return to the department after ordering and paying for only half their order. While a customer was never rude to me or anyone in my department, I can completely understand their frustration.
The pay also wasn't great.