Outbound links
The search engines are trying to give their users the best possible experience.
Thus they assume that a site that is prepared to link away from itself, to other sites that are valuable and relevant, will be a useful resource of information for the site's visitors.
i.e. if the V&A site is prepared to link to a number of sites that are also art and design-related, the search engines assume the V&A site itself is a valuable resource of information for art and design-related searches.
This is known as the site being a "hub" of information, and gives the V&A site a "boost" in the rankings for art and design-related search phrases.
This practice should be combined with an Inbound Links strategy, though (see the Site Citations section), in order to ensure the value to the V&A site of giving an outbound link elsewhere, is not negated by the fact that the other site gains value from having an inbound link from the V&A.
To this end, the V&A site should only consider featuring outbound links to sites that are already considered to be "credible" and "authoritative" (see the Credibility and Authority section).