Speculation here, but perhaps the mycoid virus eventually took it's tool on the Thargoids in our galaxy. Assuming (adding a sprinkling of speculation here again) the new ship is Thargoid, it could be actually from another, more ancient branch that never heard from their Milky Way brethren (sorry, sistren) again - they could in fact be looking back to this galaxy to see what happened to them.
It would explain why, at the moment, encounters (prescribed or not) have not been malevolent - yet.
The whole thing smacks of Thargoid (to some, myself included, not others however) yet it's been a scan-turn-and-disappear affair of "whatever they are".
The "bar codes" in the view, although some have commented that it's the helmet's reflection, appears to myself to be a light pulse transmission waiting for feedback. It wouldn't be difficult even using today's technology to point a light beam and pulse the same information.
So perhaps we're dealing with their distant relatives who have come looking for them. So best not, in the words of Bazil Fawlty, "mention the war" (nudge nudge, wink wink, know what I mean!?)
It's great sat here in my tinfoil-wear sipping tea and munching on biscuits, but pretty much the pages since this has happened has been speculation - I like that, because we can read about everyone's opinions and ideas - that's what good, hard-core biscuit-inducing science is about. All we need to do now is continue with experiments and see where it leads us - and, if necessary, see what the new ship encounters yeild from "their" perspective...