Creating links
Welcome as a new editor.
When adding links within other articles, please look carefully at what you are adding to. The links in the See also category of the Stained glass article plainly does not contain any links to individual artists or firms, as there are hundreds of them. One movie about one artist doesn't require a link in that particular list, which is of articles of general relevance to the article as a broad whole. The article needs listing in the See also section to the article on Harry Clarke specifically.