(Do not share this, it is your paid privilege.)
In the second panel the tentacles have different areas of kinetic force. At tips they are stopped by her but and scrunch a bit, trying to find their way into her. Along the lengths of the tentacles they are elongated and thrusting. The slime's body is leaning forward, putting more motion and energy into the attack.
When a woman thrusts out her chest, I see it as a sexual symbol of welcoming something in, like when a woman spreads her legs. She is presenting her breasts, and maybe her Chakras. Chakras are special energy centers of the human body, and each one has a different purpose. the one in the chest symbolizes love, so sticking the chest out may subconsciously be a display of love.
http://blog.zenward.com/wp-content/uploads/2015/10/chakras.jpg
Ironically and excitingly, in possession scenes the chest sticks out involuntarily as a physical reaction. The body, which finds pleasure in possession, contradicts the mind which does not want possession. I think possession fiction is a way for us to explore and think on our contradicting thoughts and feelings when it comes to lust.
- i v