Strange! Couldn’t find your site on the SE’s & not sure how you friends did. I can only assume they have been to your site before & have the images in there own caches or possibly have very good broadband. Still if you think the pages is loading ok at over 2000kb then no problem. Personally I would aim at a 150 to 200kb entry page & a bit higher on internal pages if needed. I assume they did go to
www.printsofcornwall.com
& not
www.printsofcornwall.co.uk as this is another image site.