Not at work you can't and you shouldn't. It's injecting something into the interaction with a coworker that is potentially unwanted.
Bringing up looks is, and this might be the only time I ever use this terminology, a microaggression. It shifts the context of the interaction from work to personal without consent. That's what in the Old Days we called taking a liberty. Now, in the Old Days taking a liberty was grabbing her as-s, but bringing up looks is of the same quality though different in quantity.
If a woman wants you to be interested in her personally she will let you know. No man in world history has ever made the first move successfully.