I've tried creating it from scratch in 2.8 but the instancing/dupli option on the texture coordinate node, doesn't seem to yield the same whole image result as it did in 2.7 rather it just maps the desert image individually to each sphere if that makes sense.
Any help would be greatly appreciated thank you :)
This is actually a known issue with From Instancer option (see here for more on that). Good news is that it's just a viewport bug, it renders just fine.
Quick tip as well since you'll have to render the image to see any updates: If you use emission shaders only you can render noise free with 1 sample in Cycles and it's super quick. Won't help with diffuse/glossy/glass etc., but for just previewing colors it may help.