You're welcome and that's relatively tiny. :) It's actually a variant of an old-school approach of developing on underpowered, older systems to maximize responsiveness. Apps, web sites, databases, whatever. I mean, there's features in modern CPU's that almost everyone has that you can optimize for. Do that for sure but make your baseline efficient even on lowest, common denominator.
Means it will run like a McLaren F1 on the modern stuff with almost no resource requirements. Ironically, it didn't matter all that much on desktops and servers. The new trends of mobile browsers and pay-per-CPU-or-whatever clouds mean it brings more benefit than ever. Especially at scale.
Thanks for pointing out this mobile testing methodology. It really helps to evaluate new CSS frameworks, which we see often nowadays.