Hello,
WoodMart theme allows creating of custom labels and assigning them to products in the store. In general, custom labels are simple product attributes as well as size, color, or any other. They have been created in Dashboard -> Products -> Attributes -> Label (title of an attribute) -> Configure terms.
You can create one or more items, assign them to the product and enable “Show attribute label on products”.
If there is no image uploaded to the attribute item, the text would appear on the product grid and on the main product image. Labels with an image would have been presented as the image.
Best Regards.