That's cos it's performing a search for those two terms together, so you're more likely to see links pages for the domain you specified.
If you look at the results you'll see your keywords highlighted in there, and THAT is where your results come from.. so if someone is linking
www.domain.com and you do a search for 'links: domain.com' then you're going to see those links come up, PLUS you'll see anywhere that it just says 'domain.com'