Tracks 1 to 6 are fully mixed songs. It is what you get when you order a mix (of course it may vary from your recording quality).
The mixing process and steps applied in these tracks examples will be the same for your songs.
Track n°7 is a a comparison of fully mixed and not mixed parts of 2 different songs. Track n°8 is a comparison of creative ambient vocal FX, after & before processing on 2 songs. It is very useful to hear what is actually being done during the mixing process. You can easily listen to the differences because the Worked and Raw sections are looped and put side-by-side.
But why do the comparison tracks (number 7 & 8) have a lower volume ? It’s because the processed and unprocessed part have their volume matched. It allows you to do a proper comparison when listening, and not be fooled by the mixed section which is usually louder than when it’s not processed. In fact the human hear tend to appreciate more louder music.