"He also slapped the BBC for repeatedly showing a burning building from three days ago as if to dramatise events, saying there are no building burnings now."

Yes, well, don't forget..."the News" nowadays has essentially 2 purposes:

1. to entertain (thus increasing the number of viewers who tune in)

2. to propagandize (thus moulding and shaping public consciousness in a desired fashion and direction)

Showing a burning building in downtown London assists greatly in achieving both those endeavours, so that's why they do it.