I think with the UI designs being implemented wrong, it could be either one, depending on how the designs are presented.
For instance say you add a fancy, colored, layered shadow to a button. If you point out “hey this shadow is 4 layers, 4 shades of red, with these different blurs and spreads” etc, and they don’t implement it, then I’d think they (a) don’t think those details matter, (b) ran out of time, (c) don’t have the CSS chops to know how to implement it (or b+c, ran out of time looking for how to do it).
On the other hand if the design is presented as a beautiful mock-up with all these fine details, but lacking specific call-outs, I wouldn’t be surprised if many engineers miss the finer details.
For instance say you add a fancy, colored, layered shadow to a button. If you point out “hey this shadow is 4 layers, 4 shades of red, with these different blurs and spreads” etc, and they don’t implement it, then I’d think they (a) don’t think those details matter, (b) ran out of time, (c) don’t have the CSS chops to know how to implement it (or b+c, ran out of time looking for how to do it).
On the other hand if the design is presented as a beautiful mock-up with all these fine details, but lacking specific call-outs, I wouldn’t be surprised if many engineers miss the finer details.