Watch the From Tiny To Junior: Solo 1 online guitar lesson by David Blacker from Swing Blues Survival Guide: Lead
The first four bars incorporate the interplay between major and minor tonalities. It opens with a double stop that has the the flat 3rd (minor sound) on the high E string, and the 6th on the B string that really grabs the ear. Then we walk down notes in the G major scale into a minor 3rd -> major 3rd -> minor 3rd riff. Again, more interplay between major and minor tonalities, giving it that jump/west coast sound.
Over the 3rd and 4th measures of the I chord, we have a riff that implies a IV chord change by outlining the key chord tones of the IV chord. Implying chord changes (where the underlying harmony does not change) is a really important west coast thing and a cool idea to experiment with in a lot of different contexts. All the licks in this piece are outlining existing chord changes or implied chord changes, so it's good to break them down and analyze them.