What does the lock image on the SL2 icon indicate?

Today I downloaded the trial version of SL2 and am noticing that the file icons on some files have a lock icon on them. What does this signify? For a bit a background, I have SL1 installed, I also have/had the SL2 Beta installed but that seems to have been overwritten by the SL2 Trial. What's the deal?

Thanks for the info... 

4 Replies