Yes! That box, the one into which you type your question or reply.
At the top of that box you should see two rows of letters and icons. In the top row, just to the right of center, you should see the word "Size" followed by a drop-down box. The link to post an image to your message is a square icon that appears in the second row, just about centered below the word "Size" and the box that follows it. If you hover your mouse over the icon, the word "Image" should appear. Clicking on that icon will open another box, with space for you to insert the URL and other data about the image you want to include in your message.
I hope this explanation will properly answer your question. It's the best I can do without looking over your shoulder. Ha!