To summarize the level is mainly stealth based and should provide players with their first glimpse within the mysterious compound. The movements of guards and vehicles within put pressure on the player to stay out of sight and increase the pace. In contrast the photo ops the player can complete slow the pace down and encourage them to explore more of the area. Clever placement of guards and structures can keep the player confined while giving the impression of a much larger play area. Many of the places you can't reach will be accessible in later levels as well.
Link to the actual level design doc: Hidden Skies - Level Design.pdf