You know how there might be a HB you like but you actually know them, from maybe before your PU days, from a social circle, or work even?
So you're trying to get out of this friendzone or a hello-only terms 'relationship'?
I had this crazy, Seinfeld-inspired idea to get out of this. I will try something like this at the office Xmas party.

Hopefully, there will be a window of time that I can isolate the target. After general chat, I will put in
"You know, Lisa, I don't know if you've noticed or if it's ever been obvious, but I really like U...S Airways". The timing of your phrasing of syllables is kinda critical! And before there's a chance for a response, plow on with any combinations of the following, all with strategic eye-contact
"I like the way their staff look"
"They seem to have great personality"
"Refreshingly different to other airlines"
"I would like to know if they are tied with any other corporate entities"
"I would like to know more of what they do when they're not serving customers"
"Do you think I can call them outside of usual hours?"
If the target has half a brain, it will be obvious what you're getting at. And if you get blown off you just never waver in that you really do like US Airways!
Am I crazy?

You are crazy!

I don't know, a year ago this would have sounded sorta like a clever idea to me. However, now that I have a much better understanding of social dynamics and a better representation of reality, I doubt this will accomplish what you are hoping. It comes off as cheesy and forced in my opinion, and even conveying the message "I like you" isn't necessarily productive.

If you want to sneak in commands then use speed seduction material to have her think about you as more than a friend. Get her in positive and aroused emotional states and link those to you. Also kino a lot and tease her like an annoying little twat. If you game her right, then after an hour you can simply grab her hand, pull her to a corner, look her in the eye, and go in for the close.

Edit: Oh, and that isn't a metaphor. It's just a statement that is poorly concealed by completely random garbage. A metaphor would be like "you're the little sister I never had!" Honestly, thinking ahead of 'slick' lines that you will spring out is usually detrimental to your success.

_________________
There are no failures, only feedback.

Just as I suspected!
Ahem, from the dictionary

metaphor: n. A figure of speech in which a word or phrase that ordinarily designates one thing is used to designate another, thus making an implicit comparison, as in "a sea of troubles" or "All the world's a stage" (Shakespeare).

simile: n. A figure of speech in which two essentially unlike things are compared, often in a phrase introduced by like or as, as in "How like the winter hath my absence been" or "So are you to my thoughts as food to life" (Shakespeare).

With the above evidence, I think I'm more correct than you are!
Although I did like the 'random garbage' observation. That really does sound like me! Did you ever see the last ever Seinfeld episode? That's where my idea came from...
Well, the fact that you said a year ago it might've sounded clever is some hope to me. The stuff you advise... I don't think I'm there yet in either study or experience to be confident in executing that. For me personally, I have a lot of female friends and acquaintances, in fact, almost an unhealthy amount. So I can afford to lose a few in trying to get a girl to think of me in that way, if not find out for sure if she does. I think it's better for me to take a few risks and try stuff that I might ultimately crash & burn with than to do nothing and just be the nice guy as always.