You need to unblock this content by setting your broser.
ブラウザーはこの内容をブロックしないように設定してください。

INFO:
You can attach images to your email messages on your iPhone or iPad either through the Mail app or the Photos app. These images will appear in the body as in-line images, but can still be downloaded by your recipient as an attachment. If...
3 Ways to Attach Photos and Videos to Emails on an iPhone or iPad