Boulders on Tycho tell of a relatively young event
Yes, those are actual boulders that you see on the surface, boulders of melt glass that were created at the time of impact. Tycho's bright streaks are thought to be mainly made of glass, which makes them stand out prominently, even against the bright Moon surface. Of course, most craters begin life with spectacular ray like streaks like Tycho, but over time they slowly fad into the background and get covered up by the ejecta from smaller impacts. What we see with Tycho is the freshly preened mane of a new arrival strutting its stuff to impress all the other craters.
Thycho in glorious closeup
When NASA returns to the Moon with its new Constellation rocket series, Tycho will be one of the sites chosen for a landing - just North of the central peak in the above image. Getting an accurate age for Tycho will help in dating the surrounding craters, and an actual landing in Tycho to analyse rocks first hand will give a very accurate age.
We are still around ten years away from such a landing under current timelines, but with the recent discovery of water on the Moon, you never know, perhaps the interest level will increase and the years to our return will decrease.
Keep watching the Moon, Spacers!
Image credit: NASA/Goddard/Arizona State University