I believe he called it a seed. When he gave it to Elayne, he explained that after using it, her ability to channel would be greatly diminished for a few months so it was not a gift to be used in a time of war. It sounds like we have a good idea now why some angreal seem so great compared to others: it seems that using a seed "creates" an echo of the original channeler's strength in the One Power and this echoed strength is captured in the item they are using the seed on. Whether it's a 1 to 1 relationship or something more detailed, it explains why a "weak" angreal, such as the one Graendal had, seemed to always give her a great advantage and also why a sa'angreal required large amounts of channelers. Perhaps RJ used the term "magnify" in the weakest way possible: to imply that it adds an echo of additional strength allowing the channeler to draw a larger amount of saidar or saidin through the angreal and then through their own connection for their use. This also explains how the facility creating the Choedan Kal could be overrun with that many channelers having access to such powerful sa'angreal: they may have been exhausted from the process and unable to adequately defend the access keys (possibly after betrayal from within) and then themselves from the attack.

It's kind of fitting that Elayne received such a gift when she was getting ready to bring new life into the world

Has anyone already discussed this? Any other theories?