what does the squiggle above the notes mean and how do you play it on the violin/ viola? (it’s circled in the picture)

"prior to 1910, these new artists were called neo-impressionists, and they believed that "modern paris" was the proper subject for their paintings."

this is the text provided by the program, disregard other answers, as they are confusing and based on loose knowledge of the subject.   : )