[expat_panama]

Indians in San Francisco were not Aztecs.

The weren't from India either -unless you stretch the time frame. 

The image of the heart and dagger that's popular in Latin America is much more graphic that the valentine from Ohio.  An Aztec link would be much more believable than no link.  Religions typically spread more by absorption-- Messiah from Bethlehem, Greeks change the name from Joshua to Jesus, Romans change the birthday from spring to December 25.  If it works, do it!

[CobaltBlue]

I was on my way to court and didn't have time to look for a better link - really shouldn't have taken the time I did take to look for the one image I found but was still drinking my coffee trying to clear the cobwebs.

Just got back, won my motion, am now going to work on a settlement demand - cha-ching! - walking on air.

It's clear to me that the artists worked from common images that they had already seen around the mission. In the far-off passages of my memory, under the cobwebs, the image which is stirring is from a travelling show of Spanish sacred architecture from Peru that I saw at the Delgado Art Museum in New Orleans several decades ago.

In other words, they didn't create the image, they reproduced it. Which is how church paintings and sculptures work, in general, everybody copies something they've already seen, but in their own way.