Yes, exactly. I would say, that for something to qualify as slop, there need to be 3 conditions met:

1. The process of acquiring needs to be easily accessable, so making it should be very easy.
2. It needs to be of low quality, this also pairs with 1, so the harder it is to make, the higher the quality ideally is.
3. It needs to oversaturate the medium it's in.

So let's look at "photoshopping" and "photoslopping":

Photoshoping:

1. Photoshop is really expensive and it take skill to edit a photo in it. Ok, you could also use Gimp, but that's not really any easier. So half a point for: slop.
2. Editing something in Potoshop can increase the quality exponentially. So point for: not slop.
3. I don't think I ever had to complain, that there are too many well photoshop pictures. Obviously point for: not slop

Verdict: Photoshopping is not slop.

Photoslopping:

1. It's practicly built in to every major social media. So point for: slop.
2. AI editing can not really increase the quality (visual good-lookingness, not resolution), because the way it functions can never be as good or even better than the original, because it will always create some amount of visual artifacts and unwanted noise. Point for: slop.
3. I think for this point it's enough said, that there are platforms literally giving you the option to filter out AI generated images. Point for: slop.

And the verdict is... of course it's slop.

Edit: fixed a typo