In the embrace of homosexuality there is the attempt to strip off the imago dei by the Lesbian or sodomite in question. Sexuality is so closely tied up with the Image of God in men and women that when one defiles and reverses their sexuality they at the same time are seeking to rip the image of God out of themselves.
The reason this can be advanced is that male and female together comprise the image of God.
Genesis 1:27 So God created man in his own image, in the image of God created he him; male and female created he them.
When a man or a woman seek to strip themselves of their God ordained sexuality they are therefore seeking to undress themselves of the Image of God appointed to them in their composite role as image bearers.
There is also the reality that in man and woman together reflecting the character of God, in all their glorious God appointed sexuality, the fact that, together as image bearers, they reflect the one and the many found in the Unity and plurality of the Godhead. In seeking to strip off their God ordained masculine or feminine sexuality there is the attempt to turn God into a monad absent of His plurality.
The embrace then of Lesbianism and / or Sodomy then is, at its foundational level, an attack on God via the means of the attempt to erase God’s Image by erasing God’s ordained sexuality placed upon the man and the woman as God’s creaturely image bearers.
This explains why this particular sin is so dangerous and why St. Paul can write,
I Corinthians 6:17 — Flee immorality. Every other sin that a man commits is outside the body, but the immoral man sins against his own body.
The lesbian and / or the sodomite is sinning against their own body because by illicit coupling they seek to disembody themselves of the image of God contained in their physical bodies as given in their sexuality.
Sexual sin is particularly primal. It goes to the core of our identity as image bearers of God. While one can never successfully sanitize themselves of the fact that they are the Imago Dei, one can so twist their self understanding of the reality that they are image bearers that the twisting begins to approach a searing of the conscience so severe that few recover.