Comment 4 for bug 327575

OK, the Librarian stuff seems easy enough to explain: lib/canonical/launchpad/webapp/tales.py does a lot of "if context.icon is not None:" (for icon, mugshot, logo, and probably more). Which of course attempts to load context.icon into memory, and that isn't really necessary.

It may have a desirable "prefetching" effect. OTOH in cases where caches and proxies don't take care of the icon, it's better to incur a bit of back-to-back latency on filling in each icon than to keep the entire page from going to the client until all these latencies have already been incurred.

I'll treat that as a separate issue.