I had to reconstruct this from the still image and the audio as I couldn't grab the video from iPlayer. Somebody played a prank on the 6:56 opt during BBC Breakfast this morning:
Excuse the bandicam watermark - shows the opt and crash to BBC London.
Someone leaving something on a server by mistake or as a placeholder that's made it to air? Find it difficult to believe that the BBC Coding and Mux has been compromised, or even a local BBC gallery...
(I was going to embed the Max Headroom incident here but I can't find a video with a thumbnail that isn't as scary as hell for it, but we all know what I'm talking about with that)
That's got to be something they were recording in the studio, and some device between the gallery and the opt switch has crashed and got stuck on that frame?
Going by what the newsreader says it wasn't a prank or a 'hijack' but some sort of bizarre fault.
It sounds like they knew there might have been an issue but gave it a try and then it was obvious that they weren't on air properly and gave up. Probably it was routed to line downstream of the gallery so they weren't seeing it in the gallery before hand
As to what it was and how come it went to air, no idea. Maybe it was something jokey recorded for a leaving tape or similar.