Symptoms
Image Control doesn't allow for anonymous control, although it is allowed for anonymous access in the web.config by default:
Diagnoses
This is known issue with the image.ashx code and anonymous properties
Resolution
Labs sent a cold fix 469.13 to patch this issue that fixes the "code Image.ashx is not compatible with the anonymous property"
The following keys needs to be added to the web.config:
End user has found a workaround and will be holding of for a later release of K2 see their work around below.
Fixed the issue by replacing the picture control with a label with an image tag that has an image url on an anonymous location.