This is in response to a blogger query. I have already said that you can't put images in comment as only certain HTML tags are allowed. Anyway I said, come to think of it, I never tried. So as a retired scientist, I will do a test to confirm. I tried to make a comment in a post in this blog. I tried to use <img src="photo URL"> in a comment and back came this error message:
Your HTML cannot be accepted: Tag is not allowed: <img src="URL">
You can use some HTML tags, such as <b>, <i>, <a>
So test confirmed what I had expected.