Well, if X is working for a manager M for 3 years at Apple(for that matter, any company), M wants to make sure that wheoever applies to X's role during the PERM process (labor certification to ensure that no US citizens/perm residents are available to fill X's role) gets dinged 100%, no exceptions whatsoever. The way they can ding applicants takes shape in different forms: (a) make the job very very specific, thereby showing that other applicants don't have specific skills (b) make the job very generic, then ask for very very precise skills that X's role needs (c) make the interview really tough (d) add extra rounds of interviews (e) a combination of all of the foregoing.