Thanks for writing in! Regretfully this isn’t a feature offered by X. It could be possible with custom development, but this would be outside the scope of support we can offer. You may wish to consult a developer to assist you with this. X is quite extensible with child themes, so there are plenty of possibilities.
Please note that you will need to add the PHP code in function.php file. Rather then editing core theme file, I suggest you to please install child theme and then add PHP code in child theme function.php file. I am sharing few resources that you can use to download and setup child theme.
I also came across a plugin that you can take a look at add Smugmug images on your website, though not exactly what you are looking for but may help you in future. You can download the plugin from following source: