Memory & loading images into an array

Experimenting with the Roku created 'fading-screensaver from github
https://github.com/rokudev/sample-channels/blob/master/fading-screensaver.zip

A simple five image screensaver that loads images form the /pkg.
I am altering to load from an xml/CDN and wanted to understand how memory purge may be handled.
That is, loading 5 images from a /pkg seems fairly low from memory perspective, but loading 100+ seems like a problem.
Is memory handled automatically in this case?

I have looked at the output using 'sgnodes all' but this is not my forte. 

Thanks for any info!