vikalpāntarāropitapratibhāsāntarād bhedena svayaṃ pratibhāsanānmukhyataḥ / apohyata ityapoho 'nyasmād apoho 'nyāpoha iti vyutpatteḥ
Primarily, because it appears by itself as distinct from other appearances superimposed by other conceptual constructions, based on the derivation "what is excluded [apohyate] from others is apoha, [hence] exclusion from others [anyāpoha]"