Oh come now, if it updated oncer per day, that's 25 seconds of flicker per 86,375 seconds of viewing. And you could set it to update at 2am when everyone is asleep.
(Computer vision would be cool though, imagine if it was different every time you left and re-entered a room?)
Humans are pretty perceptive of things flickering in the periphery of their vision, especially when they happen only rarely (as opposed to, say, xmas tree lights).
That said, you could probably put a one-cell LCD (like those shadeable windows on the 787) over the screen to black it out during the update.
(Computer vision would be cool though, imagine if it was different every time you left and re-entered a room?)