You can also link photos from Facebook (if you do the Facebook thing). Just click to view the image full size (within Facebook), then copy and paste the url here, wrapped in "img" tags.
Like this (without the spaces)...
[i m g]https://scontent-ort2-2.xx.fbcdn.net/v/t1.0-9/fr/cp0/e15/q65/19366153_1312424495492358_8777084483826154638_n.jp g?efg=eyJpIjoidCJ9&oh=c3c9d674d2c0bc3435e8c21e41f5 a42a&oe=5B13E65D[/i m g]
and it will post like this: