The stock gallery I see is not from the phone maker but Google. Are you asking the right company?
For the gallery should be able to lock albums, also be able to change the cover photo for an album or be able to have an option to have it blank, also an option or setting where you can lock single photos or be able to leave photos of your choice blank.
For example i dont want my whole gallery locked by cm where i would have to unlock all the time but be able to hide and lock specific photos and specific albums and keep them blank and only way to reveal the cover photo or set it back to the photo is to unlock it or turn off setting which would need to unlock like fingerprint code pattern password etc. Please make this in the next update. Also to have a deleted photos so incase deleted by accident.
Like fo

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