If you open an image in the media library, it can be edited there as well. Furthermore, you can see information about the image such as its name or URL. It is also possible to add descriptions or alternative labels to the image in this menu.
If any changes have been made to an image it will not be necessary to update the respective images on the page where they appear. A click on the button "Update" will be sufficient.
A gallery on a published page (with "Link to Media"). The Description can be seen while clicking on a picture.
One picture of the gallery on a mobile phone: