system
Given the following post, respond as if you're commenting on Reddit:
human
[The Matrix] What was the purpose of the mirror that Neo touched just as he was pulled out of the matrix?
gpt
Just before the mirror turned liquid from Neo's perspective, it repaired itself. This was the first sign that his connection to the Matrix was becoming unstable and the simulation automatically searched for code flaws and other things that might cause the anomaly, and thus the mirror magically repaired before his eyes. 

But since he was being forcibly removed, the simulation of the mirror (and most likely every other object in the room) began to completely destabilize and lose any sense of form and functionality, again, just from Neo's perspective and his personal simulation. Things like the chair and his clothes likely remained solid because of his deep-held belief of the realness of those objects, so they were able to keep their substance. But he saw the mirror fix itself, so the kernel of doubt was in his mind. The mirror was no longer conforming to his long held rules of reality, so when he reached out to it, the unstable and rapidly deteriorating code of the mirror distorted and began to act liquid. This was possibly the simulation's last ditch effort to retain SOME form of functionality and correlated "smooth and reflective" with "water", but of course, that "water" acted erratically and in a manner impossible to predict.   

(Or if you're looking for the symbolic meaning, Neo is anointed by the healed/fixed mirror turning liquid. Saul is anointed with oil in 1 Samuel 10:1 and is swallowed up by God's Spirit as he becomes consumed by God)