The Top Posts and Pages Widget is showing only the author's gravatar in the "Display as"
links with post images, or a grid of larger post images
There are a number of topics in the support forum about this issue:
It seems staff is working behind the scenes on updating that widget. In the meanwhile, folks are experiencing problems. If you are one of them, then either post here or in one of the other threads. They have been modlooked, so please subscribe so you will be notified about staff answers on this topic.
The blog I need help with is 1tess.wordpress.com.