how often do new pictures need to be takenof each model

Answer 1

Model? as in --

fashion?
car?
phone?

Is there a standard number of new pictures?

Please clarify.

Answer 2

products in a grocery store/ no standard

Answer 3

I don't see any reason to take new pictures, unless the packaging changes. An apple looked the same 10 years ago as it does now.

Answer 4

Not the same apple. :-)