His site takes 40 seconds to load. Everyone is saying it is because he has a lot of pictures on his site. They are all PNGs and almost all of them are over 100kb. If you download the homepage, the folder is about 1.5 megabytes when a web page shouldn't be more than a few hundred kilobytes. Fine, makes sense. Then I went to my website which loads in only a few seconds. I also have a lot of pictures. I downloaded it and the folder is also 1.5 megabytes... So what's the deal?
It could be many things, really, mate. I would use Google Chrome's "Developer tools" (CTRL+SHFT+I) to evaluate page load speed. The difference may be in http caching headers, so your brother might need to set up his site to tell the browser to cache images, CSS and JS (for example). Anyway, that's speculation. Do your research first with Developer tools. You'll find the answer that way (if it's files being loaded every time, slow server or whatever).