A little bit of news publishing history is relevant to this discussion. When laying out a newspaper page or saving a draft of an online article most layout editors required the journalist or photo editor to put a line of text under the photo even as a holding piece of copy (if they hadn’t thought of anything catchy or something which would add extra meaning to a particular story.)
Like headlines and sub heads, and the general copy this would likely be tweaked or changed by the senior copy editors anyway before publishing so a journalist writing an article or a photo editor placing a photo often didn’t want to spend hours crafting a clever pithy headline just to have it changed so would just stick anything in to ‘hold the space’ for layout.
As the photo caption is also one of the most frequently forgotten areas to check before pressing publish it is generally good practice to write something bland and sensible - every now and then some joker writes a silly caption to make his colleagues laugh and it accidentally gets published and then everyone gets bollocked by the editor.
So convention is to write a simple description of what you see and also the style convention is to write it in the present tense.
Camilla sits in the car during the King’s visit
^^
Andy Murray lies down on the tennis court during his first Wimbledon match
^^
A salmon leaps out of a Scottish stream
You are aiming for boring but accurate in case someone accidentally publishes it and you get blamed.
What has clearly happened with the Africa Nation tweet is either from a press agency pool photo, or their own in house photo editor, they have simply printed the photo and copy pasted the accompanying bland descriptive caption.
It’s not a report, it’s not trying to give you any specific information - it’s just content filler.
Every other news outlet who glanced at that tweet could see exactly what it was. Even if someone at a regular news outlet had accidentally read it the wrong way. “OMG she didn’t get out of the car???”
A three second Google of the video footage shows you she did - only fractionally later than Charles got out.
The only reason to turn that tweet into a story which claims Kenyan journalists were reporting that Camilla didn’t even get out of the car and spin it into a negative sounding incident is either malicious intent or ignorance (Celebitchy site) and blindly repeating the gossip site’s spin for click content (the scraper sites like Geo News which are bot/algorithm led, not staffed by trained journalists)