Encryption password

If I backup my iPhone using iMazing (with the encryption box ticked), then I disconnect iphone, shut down iMazing ............ then my son walks in and opens iMazing on the same desktop, is he (or anyone) supposed to be able to see the backup without entering a Password?? e.g. he can go to Notes and see all of them \? Something doesn't seem right. Any help please is much appreciated. Thanx.