If your sent messages are unread but the recipient has been online consider the very real possibility she got a message from someone more interesting and she has been so busy flirting with the new guy she is too preoccupied to clean up her mail.
That said, make no assumptions.
Also, the last contact I made with someone was one that did not have a pic. I asked "why no pic"?
The user asked I give my email address and they would send a pic. I did so. And they never sent one back.
Could this be some hacker or something messing with me. I get other emails from people not associated with POF but nothing from the people I have messaged.
Again, make no assumptions. Possibilities include:
Her mail service flagged your photo-carrying email as spam and quarantined it (and she doesn't have a clue how to check the quarantined files).
Your email got stuck in some cyber-space black hole and never reached her mail server. You could try sending it again, explaining politely you are risking being redundant but were concerned your first effort didn't reach her the first time.
She saw your photo and isn't interested.