The Media Gallery shows you all the uploaded images on the site. It is embedded on the editor toolbars of the Post Composer and Page Composer.
You can add images by drag and drop or upload. You can update image information like description and caption. The Caption of an image is particularly useful for the editor automatically put the caption if there is one under the image.
Tip: when you upload an image your file name will be defaulted to be the image caption, so give your file name meaningful names.
Limitation Currently only jpg, png and gif files are supported.
⚠️ If you publish blog posts with images from Open Live Writer, for each image OLW will save two copies.