I have a question about thinning shears?

Every few months the lady who cuts my hair thins it out with shears. Just a little over a week ago I got a cut slightly shorter than usual and she used the shears. What I am noticing is its a lot easier to see my scalp now. Can using thinning shears make it easier to see the scalp? The reason I am not sure is because basically don't thinning shears just cut some areas of hair thinner...so it wouldnt make much of a difference with how visible my scalp is? I'm a bit confused.