Residue on paint samples

I had purchased 4 paint samples and didn’t have time to use them right away. A week or so later, I opened them and noticed that the paint samples look like this.

Is this normal or is there something wrong with the paint? Do I simply need to stir them before using them?

I had purchased 4 paint samples and didn’t have time to use them right away. A week or so later, I opened them and noticed that the paint samples look like this.

Is this normal or is there something wrong with the paint? Do I simply need to stir them before using them?