It's just an arbitrary way of assigning values to the picks, so you can better understand (or attempt to at least) what sort of value you should be giving away/receiving for the picks in question.
For example, if you wanted to try and trade for 1.1, then you'd need to trade picks that have a combined value of at least that. Again, when it's being used in terms of a video game(I've no idea the scale FHM uses) it's not a hard and fast cheat code, it's just a concept to demystify pick values somewhat.
