@oncletom I'm referring to the config option `onResize` which can optionally be specified when creating a new Imager instance (see: https://github.com/BBC-News/Imager.js/blob/b7b31d795ff9d7a0cb39a9626ca426299007a1d2/README.md#onresize) - just thought that should probably be specified in that code comment block as the other config options are detailed there.

I'm going to add this myself now, but I'll just use what you've already written on the README :-)