I’m so confused

Learning to candle

I have what I can only assume is now a broody momma duck (I understand this is a chicken group) I candled eggs 6 days ago and the egg looked great could see tiny veins and what looked like a heart beat today I candled one after I smelt stink in the nest so I assume a bad egg but this other egg I can’t tell but I have a feeling it’s not alive anymore can anyone tell from this photo I know it’s not a good picture!