Once the image is in your Media Manager, click on it to insert into your question.

The image should appear in-line at the spot where your cursor was positioned when you opened the Media Manager.

iFixit images show up in 4:3 format. Most modern cameras capture in 3:2 or 16:9, which will require a crop. If you change your capturing preferences when taking pictures to 4:3, you won't need to crop them in the Media Manager.