Square: add space, keep every edge.
Take the tool’s AI-generated bottle sample, 1024 × 1536 pixels. Choose a 1024 × 1024 canvas, 5% minimum padding per side and leave enlargement off.
The whole photo becomes 614 × 922 pixels, centered on white. The export is square; none of the original frame is cropped. The longer side uses 90% of the canvas, so the shorter side has extra white space.
A larger canvas will not add detail. Transparent pixels become white, and the original background stays in the photo. For a store that crops images, first check its theme’s fit setting.

