I think the wheels in that picture look like what I have ( 5-spoke aluminum 15 x 6.5 --RPO code PF3) , and were 'optional' on the Astro vans for many years. I think they were pretty much an automatic upgrade for most dealers as part of a 'package' on the passenger vans.. . Mine is a 1998 LS.
I had a neighbor who had a non-running late '90's Silverado pickup, with the same wheels as I have on my van, but with 235/75R15 tires. I borrowed a coupe of his wheels to see how they would fit on my Astro, before I upgraded to my current 235/75R15 LT's.