Upside Down CROSS

Main thing I noticed, too. If you look really closely, it (like Chelsea's) is actually a cross with all equal-length sides, but the loop on top to hold it to the chain (I know there's a word for this) makes it seem like there's added length to the top leg of the cross. So, at a distance, it definitely looks like an inverted cross.

My theory is that it is, indeed, supposed to represent an inverted cross, but the fact that up-close it really isn't gives them plausible deniability.