It jives perfectly with a narcissistic personality. Remember as long as you reflect back to your W what she wants or expects to see....she's ok. Her cakes are a great example....narcassists need others to bolster them up, just like with her tearing her own cakes down....she does this because she expects you to praise them to boost her importance. I have no doubt her cakes are great, but that's an excellent example of something a narcassist would do.
Out of curiosity, if you agreed with her that something was a bit off on one of her cakes what would she do? Agree and be ok with the criticism....or have a meltdown because it's not perfect?