Well..., that would be more of a direct approach but you see:
You: Wow, you look just like a girl I used to date!
HB: Okay...
Then what?
To speak the truth, that opener wouldn't work because it isn't the interesting kind.
P.S. Don't be pinned down mate

Thats just my honest opinion. It will work if you can pull it off, but if you can pull it off, you would do better using some other opener.
But saying that on later stages to create more attraction is great...
PUA: Wow, you look just like a girl I used to date! ...Now I can't even talk to you.