“Sex object”too hard got for you to get? What about non-person? What about “sex toy.” The irony of pornography is that a 2-D image if a woman becomes more desirable than a real woman.
I think your example of irony is incorrect. I don’t believe that a picture is more desirable, I believe those that have problems with porn, are unable to get a woman, or do not want the one they have. I doubt there are many users of porn, that want to look at pictures of women that look like their wives.