I say this a lot, but I think the clear demarcation between rhythm and lead depends on the style of music. For example, most of the country bands I’ve been in have been quite strict about it. Blues bands, not so much. Unlike the cat in the video, you won’t often catch me not playing for more than a measure or two, unless I am purposely dropping out for a section of the form. There is almost always a harmony line, a counterline or unorthodox chord voicing to offer up. Usually only if the texture is super thick and sloppy am I gonna completely drop out to flex my pecks for the crowd. Lol, j/k....I do that every other chorus! =) Beyond solos, lead guitarists are also expected to play fills on a lot of tunes (if no one else already is.) You gotta wait for the vocalist takes a breath then play a short complimentary phrase then ends as the vocals come back in. Call and response works well for that. It can really distract a vocalist if you are contastantly noodling while they are singing. Wait for a space. In jazz, you are expected to be able to weave the lead and rhythm playing. There aren’t a whole lotta Freddie Green types, running around grinding out four-to-the-floor fat chords for a living. I don’t play a lot of metal, but in that video the rhythm player was playing more horizontal (linear) than vertical (chordal). I wonder if that is pretty standard? Guessing there aren’t so many cowboy chords in metal. Rhythm guitar playing can start to sound a lot like lead playing when they are both playing lines (single notes).