Image tiddlers can be simply displayed within other tiddlers via transclusion:

{{anki-config-screenshot.png}}

Using the img link-like syntax, you can also specify a size:

[img height=50 [anki-config-screenshot.png]]

The img syntax can also directly include images available at a web URL:

[img width=200 [https://upload.wikimedia.org/wikipedia/commons/b/bb/Kittyply_edit1.jpg?download]]

For more on including images in your wiki, see Images and Attachments.