When a participant is pinned in the UI we then proceed to mark it as selected on
the JVB. This will make the participant part of the last N set and will receive
the highest (or configured highest) video quality.

Pinning a participant at the JVB level just makes sure it will be part of the
last N set.

Since only one participant can be pinned in the UI, there is no point in pinning
it at the JVB level, since selecting it already achieved the same result.