designer of this dress

They've taken different coloured banarasi fabric strips and stitched those on to the dress to form the gala and other design elements. Any tailor in Karachi should be able to easily replicate this outfit for you.
I can see some small motifs on the shirt which could be part of the fabric, and I think they've had a little bit of gold thread work done around the gala area and on the dupatta. Super duper easy to copy!