Whit this set up, your files are on the hard disk and you access them with the iPad, via wi-fi. They dont have to get through the Photo App, but can be used directly through Snapseed (or else),then, when modified, saved in Photo App.
On the « cloud » WD software you can see the jpeg and Raw files and choose which to bring on the iPad to edit.
You can also use Affinity Photo or other softwares, without getting in the paying « Clouds » of Lightroom or even Apple.
You keep the usual file size you’ve set your camera to.
I like the « mobility » of the process, while ensuring your files are backed up (the hard disk has an SD slot and copy the files automatically)...