No pun intended - as with all the shorts, you have to have seen a certain amount of seasons of the central tv show ... in this case it is the first three seasons. It is not just so you know the character, but you know why they are where they are ... physically and mentally speaking.
So I assume you have seen seasons 1-3 of Elite - if you have and read on obviously, you might wonder why Lu is not in this ... I assume they couldn't get her to come back for this. Other characters who are not in the title do play in this too (like Omar - which being Nadias brother is quite necessary) ... we also get to see their sister ... and she plays a big role as in ... being the reason Nadia makes a sort of return ... we won't see her in season 4 since she moved away now .. will we? I know the answer to that, but won't say here of course.
It adds some extra information, but it is not the most needed of the Elite Short stories .. that said, if you are a completionist like I am ... well you probably will watch it.