The simplex supports not only embedding pictures but also includes a lightbox plugin. Read the post and check out various examples.

Dogs

Try to click on the following picture:

You see? A big doggo appeared.

Images can be centered:

You don’t have to use the lightbox feature. In that case, simply use markdown image tag:

There also can be a simple description under the picture:

My picture description.

Attributions

The first dog picture by Pauline Loroy. The second dog picture by: Marliese Streefland.