Speaking of Shiv (played by Sarah Snook), her series-long fashion transformation is a metaphor for her alignment with the Roy family business and her increasingly intense ruthlessness.
In season 1, we meet Shiv as the rebellious and (gasp!) liberal Roy. She wasn't working anywhere near her father, instead working in DC for the Democratic presidential hopeful, a Bernie Sanders-esque character Gil Eavis (played by Eric Bogosian). Season 1 Shiv had long, romantic waves in her hair, silk blouses, warm jewel tones, and one of chunkiest, cosiest jumpers I've ever seen.