I don't know artsy.net, it's probably image heavy.
But an average webpage size of over 1.5MB is not acceptable onmobile, imo: http://www.websiteoptimization.com/speed/tweak/average-web-p...
Also: http://royal.pingdom.com/2011/11/21/web-pages-getting-bloate...
It's far more then it should be. Graphics can be size optimized, SVG or jpg. A JS framework doesn't need to be 100k where most webpages are probably only using a small subset of functionality. And i also don't want to download a gazillion other JS files for web tracking and such things. Ever download on a high latency connection hurts.