A close up of a hamburger with bacon and cheese on a bun

Enhance an existing image of a hamburger to feature a beautifully crafted and juicy burger, made with a brioche bun without sesame seeds. Modify the burger to showcase a smash burger patty with a visible slice of white onion embedded in the center. The presentation should emulate the enticing visuals often seen in fast food advertisements, with the burger impeccably arranged to accentuate its appeal. The bun should be perfectly toasted and glossy, complemented by fresh lettuce, ripe tomato slices, and melted cheese melting over the sides. The smash burger patty should exhibit caramelized edges and distinct grill marks, conveying a sense of irresistible juiciness and flavor. Ensure the entire composition is set against a clean, white background to highlight the burger's appetizing qualities