Do not autoplay videos, display play button instead. Use expiring links when using S3. Do not keep originals

for avatars/headers, resize avatars down to 120x120 instead of 300x300. Set cache headers on S3 stuff, also
make it private (aka only accessible via expiring links to prevent hotlinking)

app/views/accounts/_grid_card.html.haml

@@ -1,6 +1,6 @@
 .account-grid-card
   .account-grid-card__header
-    .avatar= image_tag account.avatar.url(:medium)
+    .avatar= image_tag account.avatar.expiring_url(3600, :original)
     .name
       = link_to TagManager.instance.url_for(account) do
         %span.display_name= display_name(account)

app/views/accounts/_header.html.haml

@@ -1,4 +1,4 @@
-.card{ style: "background-image: url(#{@account.header.url(:medium)})" }
+.card{ style: "background-image: url(#{@account.header.expiring_url(3600, :original)})" }
   - if user_signed_in? && current_account.id != @account.id
     .controls
       - if current_account.following?(@account)
@@ -6,7 +6,7 @@
       - else
         = link_to t('accounts.follow'), follow_account_path(@account), data: { method: :post }, class: 'button'
 
-  .avatar= image_tag @account.avatar.url(:large)
+  .avatar= image_tag @account.avatar.expiring_url(3600, :original)
   %h1.name
     = display_name(@account)
     %small= "@#{@account.username}"

app/views/accounts/show.atom.ruby

@@ -6,7 +6,7 @@ Nokogiri::XML::Builder.new do |xml|
     title      xml, @account.display_name
     subtitle   xml, @account.note
     updated_at xml, stream_updated_at
-    logo       xml, full_asset_url(@account.avatar.url(:medium, false))
+    logo       xml, full_asset_url(@account.avatar.expiring_url(3600, :original))
 
     author(xml) do
       include_author xml, @account