I think the point of the challenge is similar to one of Kuro's goals for his Deicide (
http://elementscommunity.org/forum/index.php/board,186.0.html) Competition - although it's not something where everyone just submits ASAP and we vote, it's meant to be a goal that players/designers can strive for in their spare time for fun (And perhaps pick a few game-worthy ideas out in the process). I feel that the main problem might be is that it lacks a streamlined goal or rules to follow.
As some basic goals:
Note that the current theme is also Astrological symbols, so the card can also involve constellations, Libra, etc...
The two
main themes are Gravity and Libra - you can opt to make a card based on either one of these, or you can make a completely different card and submit to the Challenge. (To be fair cards that don't follow the current theme probably get a vote penalty.)
Cards above the Crucible level should not be accepted.
(Just as an example, Mirror Klutz (
http://elementscommunity.org/forum/index.php?topic=30087.0) could fit this month's requirements pretty well, given a few changes in theme.)
Thinking outside the box is encouraged.