The standard email width is 600 pixels, and the header banner is the first thing a subscriber sees. The maker creates headers and promo blocks for your newsletter, including a 1200×600 version for sharp screens.
Email formats in the maker: header 600×200, hero banner 600×300, hero banner 1200×600. Tick the ones you need and choose how many picture variants to make for each, from one to four.
Many email clients hide images by default, so repeat your main offer in the email text. For retina screens, upload 1200×600 and set the width to 600 in your template.
Pictures are drawn by GPT Image 2.5, Nano Banana, Seedream or FLUX; you pick the model before you start. For shapes the main picture doesn't have, the AI extends its edges, so nothing important gets cropped.