I think they are real (saggy as hell) but with a good bra, you can achieve miracles
Good bra/top:
No bra/bad support (saggy sad ones):
Way underweight - if it weren't for the bra, she'd be playing soccer with them:
No boobs but a great dress to fake big boobs...:
Jolie pregnant - big boobs:
Bikini bod - trapped boobs (flat from an angle but with a "wow boob" effect from the front)
All in all, I don't think she's got fake boobs nowadays, she just knows how to mold them with the right outfit. Otherwise her boobs change with her weight fluctuation. When she was that skinny (see yellow dress) she still had boobs though much smaller- all that tissue doesn't disappear but I bet you she wasn't too desirable without lingerie.
I used to be 36C, then got preggo and massive, my nursing bra was an H cup, then lost the weight, stopped BFing and lost my boobs. I'm a 34 C/D now and with the right bra I look like a busty lady