I did wonder about that but no one else in the picture is barefoot, which made him stand out a bit. (well also the fact he was on fire of course!
)
I also wondered whether he was meant to be black and that, at that time, may point to an "exotic" profession ; a fire eater advertising a circus or something like that - although I would have thought more exotic clothing would have been evident.
see:
https://jeffreygreen.co.uk/201-street-entertainers-in-victorian-times/
https://en.wikipedia.org/wiki/Fire_eating
He is quite clearly black skinned and he is the only barefoot person in the picture. Those two facts may be linked.
From the clothing of the crowd, I'd guess late 19th or early 20th century, but I'm no expert.
Black people were more likely to be very poor in the sort of period depicted, and therefore so more likely to be barefoot in real life. Also, perhaps black people were more likely to be illustrated in a stereotypical way as barefoot.
However, the rest of his attire does not accentuate his poverty: he is wearing clean, unpatched white trousers with a smart belt, and a smart-ish dark shirt with the sleeves rolled up as if he had been working. (Everyone else is in smart clothes.)
The crowd is showing alarm or concern rather than cheering, jeering, or mobbing him, so it does not appear to be a racist incident at the moment that it was depicted, however the earlier ignition occurred.
There is an object in the background that may be the source of ignition. I can see 2 tiny marks that may be the circular front windows of an old steam locomotive cab, with the loco facing away. The rolled up sleeves and dark shirt might possibly make him the fireman on a locomotive. However, I would have expected the locomotive to be more obvious in the picture if that was the source of ignition.
The Leighton Buzzard Light Railway opened in 1919 and was originally hauled by steam.
A few Google searches have revealed lots of bad things that have happened at Leighton Buzzard, but no clues about this image.