Sleep Light Pulsating Brightnesses

Today in school I noticed an interesting thing about my MacBook. When I first closed the MB and it went to sleep the light pulsated completely on and off, but by the time that I put it in it’s computer bag it’s sleep light was pulsating only halfway on and off (never turning totally off). I remember/ know that my old iBook G4 had a different pulsating brightness than the final revision of the iBook G4. I’m wondering if this and my MBs functionalities may have anything to do with the safe-sleep functionalities of all the newer macs. It would still seem a bit odd that my MB would have at least two different modes of activation for it’s sleep light and switch between the two while asleep, but who knows. If it does have to do with safe-sleep, then it still shouldn’t be able to use both types, when I know that the hard drive doesn’t spin up between the two, and the functionality after wake-up is the same either way. Enjoy, Alex.