Few things bother me more when looking at a printed brochure or a website than being confronted with a page of photographic portraits that are not consistent in look and feel. I looked at a website for a law firm yesterday. Three years ago I had made portraits for them of all sixteen partners and all of them were on consistent backgrounds, with consistent color and head sizes. The feel of the lighting was carried through from photo to photo.
Over the last three years some of the partners retired or moved on while nine new people were added to the roster. Unfortunately, they must have decided not to spend the money on updating the website with new images of the newcomers because each new added photograph was strikingly different. Some were done with very hard light. Some where phone-cam snaps. Others were archaic styles from another time. It's not that any one image was horrible but that the mismatch of images stood out like a red wine stain on a white silk dress. The ensuing collage of mixed styles and varying level of production quality damaged the visual integrity of the page and degraded the marketing effect dramatically.
I try to make sure that we don't have that problem if I can help to avoid it. I keep a sketch or lighting diagram of the shoots I do so I can replicate them closely if there are additions after the initial shoot. If we are doing projects with teams here in Austin and counterparts in another state or country we set a style, shoot it and then create a detailed style guide for our counterpart photographers. The goal is to be able to seamlessly insert an image into a corporate website and have it look like it matches everything else on the site.
Continuity of style is part of a company's brand. You work with the marketing people not only to come up with the style but to preserve it over time. Yes, I did send a note to the marketing director at the law firm. Yes we will probably reshoot everyone.