How can I show images in Post in rails in real time?

I'm using json.jbuilder

json.array!(@posts) do |post|
  json.extract! post, :id, :body, :user_id
  json.image post.image.url
  json.url post_url(post, format: :json)
end

And I render with js

$("#posts").prepend("<%= j render @post %>")

This is the view of the render

    .col.s12.m6.l6
  -if post.image.blank?
    .card
      .card-content
        .text-left
          = post.user.email

      .text-left.card-content=post.body
  -elsif post.body.blank?
    .card
      .card-content
        .text-left
          =post.user.email
      .card-image
        =image_tag post.image.url, class: "materialboxed"
  -else
    .card
      .card-content
        .text-left
          =post.user.email

      .card-image
        =image_tag post.image.url, class: "materialboxed"
      .text-left.card-content
        %span= post.body

And I print it on a label

#posts

I want him to show the images but he does not show them to me, but if I put only text if he shows it in real time.