high profiles have a narrower base and project more, low profile have a wider base and project less moderates are somewhere in the middle.
Im a size 8 with empty 32d boobs, im having low profiles to fill my large breast pocket tissue and fill up the emptyness breast feeding caused.
someone with a smaller breast pocket (maybe an a cup for example) would probably be better suited to a high profile as they dont have as much to fill out in the first place (tissue wise).
Of course everyone is different but thats my understanding from what the sugreon said xx