Layout images lost in subplots

Hi,

I've [learned](https://plot.ly/python/images/) that the Python interface to Plotly has the ability to import outside images as backgrounds, logos, overlays to plots, etc. I could really use this ability with some Julia code I'm working on, so I'm wondering if there's any chance this could be made accessible from Julia as well, or if I'm missing where the way to do so is documented.

Thanks!