Judge Reinhardt waxes poetic in an opinion that's somewhat replete with tangents and that reverses a misdemeanor criminal conviction (resulting in a fine of $150) for insufficient evidence.
Judge Murguia is fine with the result, but not the digressions. So she concurs. Purely, I strongly suspect, for style reasons.
There are two different views about joining the opinions of others. One view says that the author largely has the prerogative to say whatever s/he wants to say in the form s/he prefers, and that the remainder of the panel should go along with it as long as the substance is fine. The other view says to concur separately if the author's stylistic choices are substantially not to your liking, particularly when you have no strong personal attachment to the author.
Judge Murguia apparently takes the latter approach.