Does the steam cloud for saves come out of the 20gb storage for photos?

[Xarovin]

I was under the impression you had unlimited cloud backup for games (within their limits of course, so for example, 100 games at 1gb each, you could have up to 100gb total), but I've not uploaded many photos and I just noticed it's saying I'm using 1.5gb.
Does this mean you have up to 20gb of steam cloud sync, then after that it'll stop working? I have 49 photos uploaded, and they're definitely not 30mb each.