Stargirl's outfit was much better on Smallville. This one looks like it was pieced together at the last minute. Though with the other characters costumes, they could attributed to the era from which they are from. Most of the characters were supposed to be from the 1940s?
I believe the JSA episodes are set in an alternate 1940's so they need to use materials that fit but looking at the costumes side by side with their comic counterparts
Stargirl's is recognisable as the original but without the use of spandex and a bare mid-riff and the mask looks much better than the Smallville one.
Hard to do much with Obsidian's costume but it's in the ball park.
They lost Hourman's big cape and cowl, but if you've hired Patrick Adams you want the audience to see his face.
The LoT version looks like the one they arrow but despite the more muted colors it's recognisable as being Vixen.
Commander Steel looks more like a bargain basement Cpt America, but the Y shaped leather holster looks a little like the blue Y on the comic counterpart.
Dr Midnite one of only two characters in the team created in the 1940's, the red jacket is too muted, the cape has gone and the head gear just looks plain silly and not like the comic counterpart.