Illustration showing pattern pieces for this dress. It would be very easy to alter a standard a-line dress pattern to create this style. Changing the bodice darts to gathers really changes the look.
DIY Vintage Asymmetric Dress - FREE Sewing Pattern (Draft)
Tunic blouse or Baju kurung
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Cowl-necked dress. I've seen a similar design from Paco Peralta.