You solved my issue!!!
The reason I thought it was odd was because I actually had the wrong syntax
In my example i was doing {{#xlsxAdd "xl/drawings/drawing1.xml" "xdr:wsDr.twoCellAnchor"}}
In your example you did {{#xlsxAdd "xl/drawings/drawing1.xml" "xdr:wsDr.xdr:twoCellAnchor"}}
I completely missed the 2nd namespace which is what caused things to not work at all. This is why things looked odd to me but I couldn't figure out why.
As always...thanks for everything! It's a great product!