Well, the photo of the crowd tells a different story to what it was really like - my wife and daughter said the same things as what some are saying on here about social distancing. In practice, inside the stadium, because of the large concourse under the South Stand it was easy to keep well separated and everybody adhered to the face mask regulations. And with no vending points open in the concourse there was no queuing or crowding within the stadium. In fact, at half time the gates at the rear of the South Stand were opened up so that people could stand outside. There were two vending outlets outside for food and drink and both had well distanced queues. Pitch side, as somebody else has said there was a row separation both in front and behind and at least two seats separation between 'support bubbles'. Looking around, it appeared that the the 'support bubbles', in the main, contained pairs of fans rather than larger groups. There were also loads of stewards to help and advise and my impression of maybe a bit of crowding at the end of the game was the usual few people who just wanted to get up and go whatever the instructions were! And I can assure you, there were plenty of announcements about what you should be doing at the final whistle. The club also had it well organised with having vendors constantly wandering around the stand (like an American baseball match) with food and drinks on offer - everything with contactless payment. All in all, I thought the club organised it very well and at no time did I feel unsafe.
The general feeling I got from everyone was that we were all so grateful and felt so privileged to be there. If the experiment is repeated (and that probably looks less and less likely) I would highly recommend applying for a ticket and I am more than happy to not get another shot at it until all my fellow ST holders have had a similar chance.
On a final note, I would say that the club would find it very difficult to operate a similar experiment around the rest of the ground, not because of the seating arrangements but because of the narrowness of the concourses and stairwells. The South Stand is the obvious 'test bed' and I would have thought that maybe 25% capacity of it would be feasible and safe - very odd to see City fans in the away section though!