I don't know very well how to post pictures on NOSTR and at this point I am too afraid to ask
Discussion
All you gotta do is go to nostr.build it’s very easy. Don’t worry we’ve all been where you have.
I just posted a direct image link and it showed up, so guess it works. Full url of image with .jpg or .png
Click link (below)
Enter photo/video/gif
Click upload
Copy/paste link provided into a note