That's their terminology I believe (hence quotes). However, for fun you can have a go at imputing a full genome from these SNPs (e.g. http://genomesunzipped.org/2013/03/learning-more-from-your-2...). SNPs aren't necessarily exonic either so exome-seq isn't a superset of SNPs (I am a bioinformatics PhD student so while this isn't precisely my day job I'm not speaking from a position of ignorance).