glados, portal (series), portal 1, commentary, non-web source, spoilers, 1girl, bdsm, belt, blindfold, bondage, bound, brown hair, chain, encasement, female focus, gag, gagged, hair bun, headphones, immobilization, isolation, leather, legbinder, lock, navel, orange hair, padlock, personification, pinup (style), red hair, sensory deprivation, single hair bun, slave, solo, straitjacket, strap, upside-down, valve, watermark, web address