I doubt the logo is barnards loop. Lore-wise there's been about a thousand years of history where people could travel there; There's no permit systems. if anyone was in barnards loop there we would know
The simplest explanation seems to be a faction logo, There's no reason to assume it's any sort of message for us and they're not a natural phenomena. [edit] And it indicates the origin of a particular barnacle in a way useful to those who made them, not just us
Currently tearing through the game files to find some evidence that they can in fact spawn outside of the pleiades, It's incredibly frustrating to find nothing but nav beacons, not exploring again until there's some evidence and not simply a dev comment
How would the aliens see Barnard's Loop if they lived inside it? No, if the logo is Barnard's Loop it makes far more sense that the region is somewhere, maybe on the opposite side of Barnard's Loop, where it would be prevalent in the sky of their homeworld. That seems more logical, it's prominent in their sky and they identify with it.