Display campaigns moving to Demand Gen: which images to prepare

If you run Display campaigns, the practical step is to build the image set a Demand Gen campaign asks for, not only the banner sizes Display used. Google's announcement says Display advertisers will manage the Google Display Network inside Demand Gen, with a migration tool coming (read 2026-10-02). Sume cannot run the migration, but it can produce the new ratios from one source image.

What Google says changed

Google's post, dated May 26, 2026, frames this as a move of Display management into Demand Gen. Advertisers keep the option to serve only on the Google Display Network or to widen to other Demand Gen surfaces (read 2026-10-02).

Why the creative set is different

Display campaigns lived on banner sizes. Demand Gen places ads on YouTube, Discover and Gmail too, so a set limited to one landscape banner leaves feeds without a native shape. The existing size guides on this blog list the ratios: landscape 1.91:1, square and 9:16 for Shorts.

What Sume does about it

The Image API takes a prompt plus reference images, and lets you set aspect_ratio or, on models that accept custom pixels, image_size. ChatGPT Image 2.5 on Sume requires both edges to be multiples of 16, a maximum edge of 3840 and an aspect ratio of at most 3:1, so check the catalog for the model you pick before asking for an exact pixel size.

Run one request per ratio from the same reference so the product and logo stay the same. The one-reference, four-ratios post shows that flow.

• Pick the reference image once and keep it fixed across ratios.
• Ask for each ratio in its own request instead of cropping a single output.
• Review every output for text and logo errors before upload.

What Sume does not do

Sume does not connect to Google Ads, move campaigns, or read your Display performance history. It returns image files you upload yourself. Read Google's own migration guidance in the Help Center before you move a live campaign.