First of all, we've only been talking for less than an hour. Don't you think this is going a little fast? You barely know anything about me, and you want to move straight into that? You hardly know me, so you didn't know that I am definitely not the type to entertain that concept.
You're young, and probably heavily influenced by the media and your friends. Did you see Jamey in "Sierra Burgess is a Loser" sending shirtless pics before even going on a date with the person he was sending them to and think that was a good example?
We aren't dating, not even close. You're not my boyfriend. So what reason do I have to trust you? Girls are warned against sending risqué pics to their actual boyfriends because as soon as they break up, the boy might forward them to everyone.
When a girl is dating someone, there is at least some degree of trust, because she allowed that person into her life and let them stay this far, and trusted them enough to make it official. I have no reason to believe you won't screenshot anything I send you, or take a picture with another device, and send it to your buddies to brag. I have no reason to believe that you will respect my privacy.
And besides, what makes you believe I want to send any to you anyway? No self-respecting girl would actually agree to expose herself to someone that she barely knows, and doesn't trust.
And if you wanted to actually pursue a relationship with me, you killed whatever chances you had, because after that happens to a girl, they just feel uncomfortable, and it's not as easy to pick up and talk about other stuff after that. It's just awkward.
If you really want to get somewhere with someone, ask them real questions about themselves. Talk to them about what they're interested in. Get to know what they're like on the inside.
You'd actually learn a lot more about a girl if you asked about her favorite movies or books because they're subjects that mean a lot to her and reveal a lot about her personality.
It means a lot more to a girl if you tell her you to appreciate her talents or intellect rather than just her body. A person is so much more than their body, and they want to be seen for that.
For all the ladies reading this, if a guy asks you to send pics do not feel in any way obligated to do so in fear of seeming rude. If you firmly but politely assert that you're not interested, guys that are decent deep down will back off. If they keep pressuring you, it is totally your right to block them. Never do anything you're not comfortable with, and it's not wrong of you to enforce that you have standards of how you wish to be treated. And keep doing you. Nothing you did encouraged this, especially if it's someone you've never really talked to before or know.