Height and width. Or in this case width first then height. Those are the two numbers after the | . The image displayed in the post is resized as needed automatically in the browser but the SVG will still hold scale when using in the Glowforge. That is precisely what an SVG is designed for. Scalable vector graphic.
Your design software takes care of converting to correct dimensions as does the Glowforge. Most of the time. Just a few instances where the resolution scale isn’t consistent. I use a 20 x 12 art board in Inkscape and that is a good reference for going from application to application.