Can't see “Insert image” button in Gmail when composing a mail

Question

When I'm composing a mail in Gmail I want to insert an image directly in the mail's body, but there is no "Insert image" button at the top. How can I configure it to be visible?

Answer 1

There are two ways to insert an image in the body of the mail:

• drag-and-drop it from its folder to the desired position in the message (depending on your browser, it might or might not work);
• enable the Insert image feature from the mail settings and click on the Insert image button (this option requires that the email is composed using Rich formatting).
  ← new look ← old look

To enable "Insert image":

1. Go to Settings
2. Click on the Labs tab
3. Search for Inserting images feature
   
4. Click on the Enable option
5. Click Save Changes at the bottom of the page

Answer 2

Indeed, by default there is no button:

If you want to insert an image from your computer to the body of your email, use drag-and-drop from your desktop (or file manager) to your web browser.

This drag-and-drop uses HTML5 so it will not work on old browsers.

Alternatively, you can enable the button as described by Alex, but it is a Labs feature, so it "may change, break or disappear at any time".
I guess Google just wants us to become familiar with HTML5 drag-and-drop.