To start, it's a sweat shop. Employees are expected to put the company in front of their personal lives with long working hours being the norm. Time off is frowned upon and flexibility is not really tolerated, despite some cosmetic efforts by HR to institute "flexible working hours." There is very little recognition for hard work or a job well done.
Most efforts revolve around serving the demands and needs of top management (almost all of whom are Korean) - deferring to authority and following orders. It's a "Just do it and don't ask questions" culture. It is a fairly formal and very top-down environment with the overriding principle being that the higher age/title is always right. There is little room for dissent, creativity, or autonomy. Work is often taken from the worker bees and presented by their bosses with little to no recognition of who actually did the work. Seasoned local professionals are often treated like children. Employees generally seem demoralized and beaten down - this is immediately apparent to almost anyone who walks through the dismal office.
The overriding issue at SEA is one of Korean domination. Decisions are made almost solely by Koreans in secretive backroom meetings in Korean. Local employees are just expected to follow orders from Koreans. There seem to be parallel HR policy systems - one for Korean executives providing certain budgets/travel policies and the other for everyone else. There is a de facto segregation between Koreans and locals, even at lunch. You're either a part of the Korean HQ contingent, in which case you'll get perks/responsibility/opportunities, or you're not, in which case you're just expected to obey orders. Communication of a vision, objectives, etc. is horrible. Information hoarding is also common. Local employees should not expect career progression, movements throughout/up the organization, or many chances of promotion. If those things do happen, it's after a very long period of paying dues and implicitly pledging loyalty to the Samsung way of working.
Maybe Samsung will one day truly globalize and open-up, offering equal opportunities to everyone and treating people fairly and like human beings, but that day does not appear to be anywhere in the near future.
Don't do it, unless you're 1) Korean with a strong orientation to a highly-structured command-and-control environment, or 2) really desperate for employment!!!