Something the glyphs around the circle could represent, assuming that they're in binary:
| - - = Hydrogen (1 proton)
- | - = Helium (2 protons)
- - | = Beryllium (4 protons)
- | | = Carbon (6 protons)
So it's the sequence of elements formed in a star.
Can anyone take this further? Maybe it's something like the type of stars barnacles prefer? Or it's just to show that they're aware of this (Voyager record-thing).
To add to this: the UP could be saying: "These are carbon-based lifeforms (the four glyphs), who originate on planets (the globe), who build structures on planets (two bottom left spikes), who also can also fly in the atmosphere (top left curve - yeah, I know), and who can travel off planet (top right double curve). Not sure what the line means!
Right: sorry for quoting myself, I'll shut up now, and apologies if anyone has already come up with this.