Kubernetes Volume snapshot: Why is restoresize when we list snapshot not in sync with actual volume size

Question

I created a PVC and wrote 50G of data to the volume after mounting it to a pod. Created volumesnapshot and restored volume from snapshot. Verified 50G of data is present in new volume from second application pod.

Now when I do kubectl get volumesnapshot, I see

kubectl get volumesnapshot
NAME                            READYTOUSE   SOURCEPVC                    SOURCESNAPSHOTCONTENT   RESTORESIZE   SNAPSHOTCLASS        SNAPSHOTCONTENT                                    CREATIONTIME   AGE
snapshot-csi-block-pvc-custom   true         csi-block-pvc-custom-three                           1Gi           vpc-block-snapshot   snapcontent-c2045897-7a69-4fd5-851d-b11bbade8a2f   19m            19m

I dont understand why RESTORESIZE is 1G. Have I missed something to understand in this snapshot concept.