This means that the thumbnail (includes GIF’s and video stills) seems to be of low-quality. Thumbnails (includes GIF’s and video stills) must be sharp, cropped well, not overly discolored or distorted, and must have minimum original dimensions of 1000px in length and 600px in height. For more information about thumbnail requirements and recommendations see here.
How To Fix This
Amend the high-resolution GIF or image in the thumbnail or still video image slot and resubmit the ad.
Some common explanations why campaign ads get rejected for this reason include:
Stretching small images to meet the minimum dimensions; this often reduces the image resolution or distorts the image.
To learn more about this rejection reason, see thumbnail technical requirements here and thumbnail best practices here.
To learn how to fix and resubmit your campaign or campaign ad, click here.
✅ If you have questions or concerns, contact your Account Manager, email support@taboola.com or contact our support over live chat within Realize.