Hmm, after tinkering around a bit, I think according to https://github.com/yWorks/svg2pdf.js/issues/82 , the mask element in the giraffe SVGs is not supported in the PDF converter. It is just dropped, leafing the qraffe rather qr-less.
But I sadly know neither svg enough to think up an alternative approach, or a JS/TS dev enough to see if there are other libraries.