Same thing here.
It’s because of this stupid line of CSS in the Simple Image Sizes stylesheet:
#regenerate_message, #time, #thumb {
display: none;
}
It’s so generic and so unspecific, that it fits almost everywhere; #thumb does in this case. All this wouldn’t happen if the author followed best practice and only included his stylsheet on pages where it is needed – not polluting everyones admin interface.
For now as a workaround, you could:
1) Hide the picuture column on the products page by using the settings under Screen Options
2) Comment out this line in Simple Images Sizes stylesheet
3) With something like this add the following line of CSS to your WordPress, that should catch the tables in the admin area:
/* Fix display bug caused by simple image sizes */
table.posts th#thumb { display: table-cell !important; }
Hope it helps for now
and hope there will be an update soon!