Creative
Thumbnail
The image asset of a native ad creative.
Thumbnail (or 'image' or 'asset') is the visual element of a native creative. Platforms recommend 1200×800px+, JPG or PNG, no text overlay (Meta-style limits don't apply on native, but Taboola enforces 'no logos covering more than 20% of image'). The number one variable for CTR.
Example
Identical headline tested with 14 thumbnails: stock-photo angles ranged 0.2–0.5% CTR; UGC-shot phone-camera images hit 1.1–1.4%.