Please keep in mind that your reviewer comments serve two purposes: 1) document/justify your scoring, and 2) provide feedback to the author. In my opinion (and hopefully, yours), providing authors with our feedback is the most important of the two.
With the exception of the Eyes-Only section, ALL your comments are shared (anonymously) with our authors on request. Other than the #1's written review, the comments you submit with your scoring form are the only feedback our authors receive. Therefore, please keep in mind that if you only provide "Eyes-Only" comments, unless you're the #1, the author will receive NO feedback from you!
If all three reviewers were to do this, and the book in question was also scored below the "low-score threshold," we might have to refuse to do a review, but could not tell the author why.
Thanks!