No photo, but yesterday morning, whilst cycling over Putney Bridge in London at 10.45, there was what I thought was an Airbus, either A340 or A380 descending towards Heathrow. I was only seeing it from the rear, which is why I couldn't really tell what type it was.
However, that's not the unusual bit. Inboard from the No. 3 engine on the starboard wing was another engine pod although it was definitely smaller than the working engines. I know airlines do sometimes ferry replaced engines in this way, as about 20 years ago I saw a 747 in a similar configuration, but I thought it was odd that it was clearly a smaller engine.