Spatial light modulators in the terahertz (THz) band have lagged behind their visible and near-infrared counterparts, despite growing demands for miniaturized, integrable, and multifunctional THz systems. This raises the question of how to realize optically addressed phase-type THz modulators with efficient, independent pixel-level programmability. Researchers propose a compact VO₂-based programmable metasurface functioning as a 2-bit phase-type spatial THz modulator, enabling full 2 pi phase control per pixel and zoom meta-lensing, focused vortex beams, and holographic imaging.