Does this mean lambda phage form is some sort of biology's equivalent (or as close as it gets) of a universal constant, or rather — was the genes that encode the 'container' (apologies for my lack of correct terminology here) the same, and the viral payload different, or is it also the case that the 'container code' is also unique between these viruses?
Maybe this is somewhat true for bacterial viruses, but it's worth noting it's not universally true for phages. eg see [0]. And I can't think of any mammalian viruses that are lambda phage style lunar landers. Sometimes, virses are cyclinders [1] or some kind of roughly spherical geometric structure [2], although some are just kinda blob shaped [3] enveloped viruses (some viruses have an envelope-capsid-envelope structure).
0. https://en.wikipedia.org/wiki/Phi_X_174 1. https://en.wikipedia.org/wiki/Tobacco_mosaic_virus 2. https://en.wikipedia.org/wiki/Mimivirus 3. https://en.wikipedia.org/wiki/Influenza
One thing is certain and that is that we have barely scratched the surface of genetic diversity on this planet.