Electric Lightning strikes the word into existence. A bolt arcs across the frame, the text flashes on with it, and residual current crackles over the letterforms afterwards with the edges visibly distorting.
The crackle is genuine turbulence, not a texture: feTurbulence generates a noise field and feDisplacementMap pushes the glyph outline along it, so the distortion follows the letterforms. lt-strike, lt-strikeBolt, lt-arc and lt-flicker are sequenced so the bolt lands a beat before the text resolves.
That is the displacement map doing its job — the same technique real compositing software uses for electrical distortion. It is strongest during the strike and settles afterwards.