What does a vertical line to the left of multiple staves indicate to a musician

Unit 10 explores photographs with movement in them such as wildlife and documentary photography. wilkes takes the idea of movement in photography to a different level. do you feel the tips and information that you have learned in unit 10 is applicable to the type of photography that wilkes does? someone plz me, my school gets out tmr and i need this to be done before 2oclock .