not a theorist but as an amateur filmmaker here's my take on the mv's symbolism (thread)

a recurring theme throughout the entire mv was the "line" which is interpreted in many ways. there's an actual red line, there's a cliff in sana's scene where she wants to step over it +

we have the red line that crosses their faces, this scene with jihyo with the white line and the glasses. +

we also have the white cloth above mina, the "line" that she wants to go across. and these strobe lights that form lines and the members run crossing the lines. +

surprisingly, i thought the platform meant nothing but i realized platforms have those safety lines on the floor before you ride the train

it really meant they crossed these lines to ride the train and give in to temptation +

i also noticed everytime a line is touched or crossed, something bad happens. the table was destroyed after touching the red line. the white line turned red and the glasses if water fell.

all of them riding the train at the end meant they gave in to temptation, they crossed that imaginary line, even if it meant leaving a disaster waiting to occur.

additionally, i dont have a plausible theory on what jeongyeon's character is but she always seems to be /in/ the line or she's THE line.