Device to hold heads still during the long exposure time required to make a daguerreotype portrait
Not sure why you are suggesting they only did that for dead people- long exposure times were very common in the old days and peopel often had to have soemthing to rest their heads agaisnt to keep from moving as best as possible- you will also note that not al ot of folks were smiling in the old photos- which likely was because they couldn't hold the smile for that length of time without moving their lips or mouths- it is claiemd- which is entirely possible. Also- photographers used heavy makeup