So uhh, I made an oopsie. You see, About 10 minutes ago I uploaded a real-life picture of my cat onto Newgrounds and rated it mature and titled it "Evil Kitty." Now I did not know that New grounds couldn't allow you to post real life pictures on there. I mean Deviantart could let you upload real life pictures so I thought New grounds were the same. And someone called me out on that so I immediately deleted the picture finally realizing it was a broken rule.
And please understand that the joke of the picture was that the picture was rated mature yet the only thing about it was that it had a kitty doing nothing. I only meant to make people laugh, I'm sorry.
Yatsufusa
Unless you got banned from the Art Portal over it (unlikely) and do not break rules all of the time, then you have nothing to worry about.
That being said: Read the rules to steer clear of such issues in the future...
https://www.newgrounds.com/wiki/help-information/content-submission
https://www.newgrounds.com/wiki/help-information/terms-of-use/art-guidelines