The question that you asked sounds more as a research question answer for which you need to look for in your thesis. I would recommend you to think first more broadly on VL skills and then more in your own context.

Do you only think about photojournalists? Or photo-editors as well? You may take a look at some of the English-language publications by Jenni Mäenpää from Tampere University in Finland. She is looking at photo-editing practices in a newsroom, but from the journalistic/media scholar point (so you will not have direct references to VL, but these can be helpful anyway).

If it helps, I study the influence of technical elements in film aesthetics. I analyze separately image generation and image postproduction. Im guessing you could do the same, as the skills needed to achieve a picture and edit it are different.

Photojournalists and Videographers are capturing history as it happens, sometimes for daily consumption, sometimes for long-term use. As a "Shooter" for a Detroit TV station for well over 3-decades, I have covered everything from the White House and Shuttle launches, to Healing the Children surgeons spending their vacations in a remote Columbian hospital treating young patients- and everything else in between. I've see the good- and the bad.

It is important to capture as much as possible going on around you. An understanding of the situation is important- and this calls for good communication with assignment editors, producers, editors and especially with the reporter you may be teamed up with- before, during, and after the shot is completed. I want my best video (or shots) used. In deadline news- the haste to get "On the Air," may leave the best material behind, if you don't tell someone about it (or only send them your best stuff)!

Composition of a still image is even more important for photographers than it sometimes is for videographers. They often get but one chance to get the "Money Shot." Video, by nature of the shooter being able to provide camera motion (pans & zooms), can sometimes use this effectively to show more of a scene- but this can also be overused. Study the winning images of various photo competitions- be they for news or nature- you can learn a lot about excellence in photo composition! (The same goes for video awards.)

Video is nowhere as effective without great audio. Video editing requires careful attention to not only using the best clips visually, but making sure the sound captured augments the storytelling. A mentor of mine early on told me, "People make the pictures." I have never forgotten that!

I also fight for my right a a photojournalist to capture what is going on. Too many people- from police- to common citizens- try to tell shooters NOT to shoot something! I have every right to be somewhere capturing events- be they tragic or emotionally-charged. I am not there to cause interference or harm, because sometimes a story must be told- a wrong must be revealed, in order for society to become informed. I have always taken this right to be most important!

I believe that if I have done my job well, my community and society in general will benefit by getting an honest portrayal of the resulting story or report- be it a crooked (or honest) politician, a family tragedy, or a remarkable story of courage. My goal each day was also to be welcomed back to the venue I was sent to, because I was fair and honest with my subjects and subject matter. I hope this helps with your research.