Trying to use the phoenix helper snippet I get a compile error:

== Compilation error in file lib/my_app_web/views/cloudex_image_helper.ex ==
** (CompileError) lib/my_app_web/views/cloudex_image_helper.ex:15: undefined function picture/0

I guess that's a leftover and is meant to actually read options[:width] instead of picture.width etc.?
Or is picture some convenience function of Phoenix that I'm missing?