Illustrate a whimsical group portrait of three children in fanciful costumes, standing before a backdrop of intricate, oversized paper flowers. Render the scene with precise cross-hatching to create subtle shading and texture, emphasizing the folds of their costumes and the delicate patterns of the paper flowers. The characters should have simple, slightly exaggerated features, maintaining neutral or enigmatic expressions, evoking a surreal yet playful atmosphere characteristic of Gorey’s style. Design the background minimally, allowing the focus to rest on the children and the detailed floral backdrop. Use symbolic elements subtly--perhaps a single hidden black cat peeking from the flowers or a faint shadow of a bird--creating a sense of quiet mystery. The overall composition should balance whimsy with an undercurrent of melancholy, encapsulating a moment that feels both festive and slightly detached from reality, as if pulled from a peculiar, dreamlike narrative.