The particular approach that you mentioned (S40_flyer) above is odd for two reasons, and one of them is the reason that you don't understand the question (because on this approach the question is not applicable).
Anyways, here is why the ILS 25L at LAX is odd.
1. You see the # sign next to the 3200 at or above restriction in the profile view? The note tells you that you can proceed all the way down to 1900 when authorized by ATC. Most approaches just have you down to the final approach fix altitude before glide slope intercept, but this approach is odd, because depending on what ATC tells you, your final approach fix altitude seems to be either 1900 or 3200, depending on what they say. So if they tell you that you are cleared to 1900 following HUNDA, you could pretend that the 3200 foot restriction isn't there, and intercept glideslope at 1900. Otherwise, you have to only descend to 3200, and intercept glideslope at 3200.
2. You see at LIMMA there is a 1900 at or above restriction? This is normal at the final approach fix (which is what the big black "X" is telling you). Above that "X" 1900 is printed again in smaller type, and
that 1900 is your glideslope intercept altitude. What that is telling you is that at LIMMA, when you are on glideslope you should be at
exactly 1900'. This is odd because on many approaches they are off by a couple of feet. As an example check out the ILS 13C at CBM here:
http://204.108.4.16/d-tpp/0607/00091I31C.PDF which demonstrates the point. The Final approach fix is at LESSE and is a 2000' at or above restriction, but the glideslope intercept altitude is 1913. So they are off by 77'. If you were flying this as an ILS, you would descend to 2000' after SNAEK, (or you would be vectored to final at 2000'), and then upon intercepting the glideslope you would start down. If you had DME, you could cross check that at 5.8 DME you would be at exactly 1913' if you were on glideslope. If you were flying this as a localizer, however, you would stay at 2000' until 5.8 DME, and then start your descent, so you would be descending
slightly later, and remaining
slightly higher at LESSE. But only by 77'.
Anyway, the question (if I'm understanding it properly) dealt with cases where the glideslope intercept altitude and the final approach fix altitude are different. The answer is, you only descend to the final approach fix altitude and no lower, until you intercept the glide slope, and then you follow the glideslope. The glideslope intercept altitude is there for you to ensure that you are intercepting the glideslope at the proper point to verify all the equipment is working properly. It is also there because the glideslope antenna puts out incorrect or phantom glideslope signals that you can hit if you are well past the normal glideslope intercept point, and they don't want you to follow those down unintentionally.
