I don't think you actually need to "relate the two Views displays" in the way you are thinking.
This is a bit confusing in Drupal, because Views (provided by the Views module in core) have displays. But Content Types also have configurable displays, which are sometimes referred to as "view modes," so there are different meanings of "View" and "Display" depending on whether you're configuring the presentation of a Content Type, or configuring the Views module. You'll need to understand both meanings to accomplish what you're trying to do.
(I generally use "Views" with a capital V when referring to the Views module, and "view modes" with a lowercase v when referring to content displays -- but Drupal itself sometimes capitalizes "View mode" and people use the terms interchangeably on forums, so just be on your toes.)
You've already got the gallery View set up to display thumbnails of the images from your Article content, so it's likely that in the View, you have configured Show: Content | Teaser by setting the row style options to Content with View mode: Teaser.
You can easily link each of these thumbnails to the full content of the Article by configuring the Teaser display of the Article Content Type:
Click on the gear to configure the Image field, and set Link Image To: Content (under the FORMAT section). This will automatically link each thumbnail to the full content item.
The "full content item" is the Node, and it does not need to be part of any View. Instead, you can just show the pager in a Block on the Node.
This blog post shows one way to set up a pager that might work for you.
It uses the Drupal 8 Pager module, which might simplify the configuration -- but it should also be possible to implement this in straight Views by creating the pager as a Block display and then placing its Block in a theme region for content type Article, using the same technique described in the blog post linked above.
EDIT: I think maybe you want to create multiple Pager blocks (one for each taxonomy term) and have them appear on the Node pages of your Article content. Could you edit your question to clarify whether this is what you intend?