Although we suppose it could just be a trick of the VFX light, a second look specifically at Cara Delevingne’s waist seems to support our earlier conclusion: Suicide Squad seems to have wanted Cara Delevingne to look model perfect, which is rather ironic, because Cara Delevingne was already a model before she got into acting in the first place.
It’s also worth pointing out that Delevingne herself has spoken out about the impracticality of female costumes in superhero movies before.
Along with all of the cool stuff that the VFX added to Cara Delevingne’s costume, including a glowy aspect to those tattoos, a headdress and a hipper, darker look, if you look at the full body image above, the VFX look at Cara Delevingne seems to be slimming her waistline and making her look even thinner than she already is.