I've seen that concept art before, I'm pretty sure it's on disc 2 of the special edition of Alien. Technically, Gger didn't design much of the creatures in th alien series. He designed the original drone but that was about it. He did concepts for the facehuggers, but they ended up looking like a hot water bottle with legs, the chestburster was designed by someone else also. The queen came from the mind of James Cameron, who actually designed the creature himself, & the runner from A3, even though Giger's name is credited to it, was actually majorly designed by someone else (Giger got a bit annoyed after that).
So technically, we can thanks Giger for coming up with alot of the designs in the first movie (the landscapes & the drone) but not much more than that.