There is the possibility to give pictures a description. This description will appear on the image when you roll over or in the large view below the image.
Note: You need to resize and compress the images in Photoshop (image editor). We don't have any software on wordpress that supports that.
There is a picture gallery for each category.
Here you can add, sort (drag and drop) or delete (x on hover) images and also enter descriptions for the image.
Note: The structure with the folders is an extra tool that organizes the media library. The media library in WordPress has few possibilities to sort.
If the folder structure is not visible and the media library behind it, all images are sorted by the setting date.
You can also add images then.