Commenting gallery items
I built 2 gallery type sites with album-image and category-product relations last week - my first 2 Drupal 8 sites! If direct modules are not available, you can try using views to solve your problem by creating your own gallery setup (if acceptable).

Step 1: Create provision for gallery categories

Create a taxonomy vocabulary named gallery_category and add relevant fields to it. These would serve as albums:


image: album cover
body: album description


Step 2: Create provision for gallery items

Create a content-type named gallery_item and add relevant fields to it:


image: the image
body: image description
category: reference to the gallery_category vocabulary - you can have single or multiple values depending on whether your images would belong to one or more categories (as per requirement).


Step 3: Set up views


Create one view to display a list of all categories
Create another view or modify the default taxonomy term view to fine-tune the list of gallery items inside a category.
For the views, if you have too many categories or items, make sure you enable paging or some other relevant solution to make sure all items don't load in a page.


Note: This is a general answer to try and help you. Modify the steps and details as necessary to achieve the output you desire. Good luck!