www.dailymail.co.uk/news/article-4611862/Man-jailed-posting-Grenfell-Tower-victim-picture.html
Apparently Mr. Mwaikambo, who is of Tanzanian origin or extraction, opened a body bag at the Grenfell Tower and posted the picture on Facebook.
I'm not sure about Tanzania, but I am in Indonesia and it's very common to post selfies with dead (i.e. in the moments after they die) relatives etc. on Facebook. There was a case earlier this year where a Western man died and the local newspaper published multiple shots of him dead, dressed only in his underpants with blood coming out of his nose etc. Those photos remain online.
Obviously this is not the done thing in England, but it seems that someone they have come up with a fairly arbitrary charge (sending obscene materials over the internet) - there's no law against what he did, per se - and whacked a rather stiff sentence on him.
I'm not saying he was right to do it, but it seems that there is an excessive sentence for someone who broadcast to a fairly limited number of people (he has a couple of hundred friends on Facebook), something which inherently is more about outrage at the fire than the fact of what he did.
The law used is obscenity, but the photos are no more obscene than going to Tanzania/other parts of Africa and taking pictures of dead Africans to be broadcast on the news, or photos of the deceased Gaddafi (widely distributed in Western media) or whatever. The obscenity is the fire, but Mr. Mwaikambo is in no way responsible for that.