Yes you can post pictures. When posting, open the attachments option to choose a file from your mobile device or computer.
Please note that we do have size limits and that most devices these days have very high resolution cameras. If you are having trouble, try using image editing software to crop or resize your image.
You can also use image sharing services like
Google Photos or
Flickr to host your images and then place the URL your post using the
image button.
Try quoting this post to see an example.