"La recalcada concha de tu madre."
The closest translation would be "your mother's pussy" but with added emphasis by the word "recalcada" which would be something like... uhm... super-copied? Yeah, don't ask.
I recently learned that la concha de la lora originates in old slang in which lora was commonly used to refer to prostitutes.
It makes sense. I didn't think it really applied to birds 🙃
Interesting, I didn't know that! That usage of lora was completely lost. Being an old guy, I sometimes wonder when I'm writing some slang if the younglings will understand it. Although lunfardo should stay pretty stable as a kind of side-language, no?