Mobile and desktop traffic:clarification needed.

So I just started messing with ig and cpa and I got accepted into cpagrip.
I checked the list of offers available and seen some offers termed as mobile while others are desktop.
I would like to know the difference between the two. If an offer is desktop offer does that mean if I send a traffic from Instagram to such offers it wouldn't convert since all ig users are on mobile..
Similarly if an offer is mobile offer and someone convert from desktop does that mean I wouldn't be paid?