How do I view the author of a comment in a view block?
To place a view block next to each comment use the module:

EVA: Entity Views Attachment

Create a new View for user, add an EVA display, connect it in ENTITY CONTENT SETTINGS to the Entity Type comment, the Bundle default comment and as Arguments provide the token for the user id [comment:author:uid]. Add a contextual filter for the User ID.

Now the EVA views block appears in the Comment Type and you can place it in Manage Display.

You can also use as Argument the comment id and connect it to the View you have in the question which is based on comments and has the author as relationship.