Glad you're having fun so far.
A lot of things, including labels and buttons, have an :icon property
which you use to set their image. Of course it takes Swing icon
objects, but that's pretty inconventient so it also takes URLs or
strings that look like URLs. So you can do:
(label :text "FOO" :icon "http://example.com/path/to/foo.png")
but you don't really want to download that icon every time you run
your app, so you can put it on the classpath and access it with
clojure.java.io/resource:
(label :text "FOO" :icon (clojure.java.io/resource "my/project/foo.png"))
in a normal lein project, png would live in src/my/project/foo.png or
resources/my/project/foo.png.
Finally, you can also set the icon (and text, colors, fonts, etc) from
a resource bundle using i18n stuff as shown in this example:
https://github.com/daveray/seesaw/blob/develop/test/seesaw/test/examples/j18n.clj
Hope this helps,
Dave