For example post #7765948 is from a pixiv image collection. On the left side, the source link is https://www.pixiv.net/artworks/119969206 , but https://www.pixiv.net/artworks/119969206#3 is a much better link, since it opens the collection, and jumps to the image.
I suggest that the pixiv post id recognizer should recognize the number of the image (it is easy for current links at least), and point to it directly. (Maybe not for the very first images, that probably would be confusing for pictures not in a collection.)