pryso, missed your question; sorry about that.
You are exactly right; so that not all the stands of (in this case) violins have to turn the page at the same time. Notice that the violins with pages 1&2 of the music showing are also on the outside, closest to the audience. Optics.
This is the job of the orchestra’s music library. Photocopying page 2 of the music which is often on the backside of page 1 makes it possible to have both pages visible without having to make a page turn. Sometimes music publishers don’t pay enough attention to where it makes most sense to put a rest written in the part and the player is forced to make a very quick page turn; sometimes even in the middle of a phrase forcing the player to have to play a measure or two from memory.
Of course, in any given score not all instruments have the same number of notes to play and while the violins may have two pages of music in the first movement of that concerto (as is the case in this work) a different instrument or section of instruments may have all the music for that movement on just one page.
Hope this helps and best wishes.
