My friends new chihuahua's eye glow firey red in all photographs no matter what angle( I call them satan eyes

). CHloes eyes glow green in some photos. Pennys eyes just completely reflect back light. And I dont get much of a glare with Tink. So what scientifically or medically makes them reflect different colors? I am so curious now. I know its not just based on the breed either because my chihuahua doesnt have "satan eyes" like my friends chi.