Upload URLs on subdomains of Multisite network using mapped domain

Is there a way for the file paths of uploads/scripts/other assets of the subdomain sites in a multisite network to also show as the mapped domain?

For example, my site beardspo.com is on a multisite network with the main site being websourcery.com -- when I look at the source code, all of the URLs for files show the full subdomain path. ie. http://beardspo.websourcery.com/wp-content/uploads/sites/7/2015/06/Last-Minute-Fathers-Day-Gift-Ideas.jpg

Much to my confusion, sometimes the filepath when I open an image in a new tab, doesn't include the "websourcery" part like this: http://beardspo.com/wp-content/uploads/sites/7/2015/04/Hirsute-Of-Happiness.jpg

Came across the issue after noticing my sites were being indexed twice, as both the mapped and subdomain versions. Full explanation here: http://websourcery.com/prevent-google-indexing-subdomains/ ... thinking I will need to edit this post as now Googlebots go to crawl my sites and can't reach any of the image paths because I've blocked them to fix the duplicate indexing issue (on top of the usual 301 redirects that I did over a year ago when I set it all up).