I think that it is never that straightforward. They always look at the entire package, but I think here is how it works (at least this is my impression of the process):
1. They use GMAT scores and geographic locations to put people into buckets;
2. After they have their buckets organized they break them down into smaller "sub-buckets" based on industry and work experience;
3. If there is not enough prestige in your work experience, they might look for it in your academic background and GPA or extra-curriculars;
4. They want to know WHY you need an MBA. So they will read your essays. Your chances will be affected negatively if you have prestige everywhere, such as MBB consulting, HYP undergrad, but come off as an immature individual in your essays. And on the contrary, if you don't have prestige in your experience or education but have a unique story to tell, your chances will be boosted;
5. Recommendations are there for QA purposes.