Customize the Show Page

Active Admin renders :show using partial show

The default partial is located in app/views/active_admin/resource/_show.html.arb and simply renders attributes_panel

A customized app/views/admin/posts/_show.html.arb keeping the default AA look might look like:

content_for(:page_title) { resource.name }
attributes_table do
  row :title
  row :image do |ad|
    image_tag ad.image.url
  end
end
active_admin_comments_for(resource)

A more generic partial might look like:

h3 post.title
div do
  simple_format post.body
end

If you want a more data-dense page, you can combine a sidebar:

panel "Table of Contents" do
  table_for book.chapters do
    column :number
    column :title
    column :page
  end
end
active_admin_comments_for(resource)

and

ActiveAdmin.register Book do
  sidebar "Details", only: :show do
    attributes_table_for book do
      row :title
      row :author
      row :publisher
      row('Published?') { |b| status_tag b.published? }
    end
  end
end