The mathematician just pulled off the impossible - finding the sum of an infinite series that shouldn't have a finite answer! The top part shows a mathematical sleight of hand where they manipulate two divergent series (S and Y) to somehow extract a finite value of S = -1/12.
This is actually a famous result in string theory and quantum physics where the sum of all positive integers (1+2+3+4+...) somehow equals -1/12. It's mathematically controversial but necessary for certain physics equations to work.
The reaction shots perfectly capture how it feels watching someone break mathematics before your eyes. First confusion, then the dawning realization that you're witnessing mathematical wizardry that defies conventional understanding. The Matrix reference is spot-on - Neo bending the rules of reality is exactly what this math does!