Wow, that youtube clip is is essentially the contents of the Laserdisc in presentation (without the
VT clocks). The first one is obviously the main Ident with the 1'00 music hold. There was also a short version of that and a slow version too (I think there were versions without music holds too). The plain flags that followed were very rarely used on air. They could be used as backgrounds for graphics, often line-up menus, made in the presentation suite, though most network directors didn't bother and just used a static background. The blue flag background was the one for obit/very serious news days!
The breakfiller was a brilliant but slightly tempramental bit of kit, hence the inclusion on the disc of a generic one. The ABF (Automated Breakfiller) was a Mac, connected to a laserdisc player. When the director 'stood up' a break (Cue dots on, open talkback to regions) the Mac would cue the laserdisc to a background of suitable duration and acquire text from Ceefax for News, Sport, Business, Channel Schedule and the seldom-seen Weather segments. When it had done that it would display a white bar at the top of the preview screen in the pres suite so the director knew it was ready. If it didn't do that, you had to instead get a Menu to air. The whole thing, if it was in a good mood, could be ready to go within 20seconds, though we used to tell news to always give us a minute's warning

. On transmission the Mac would run the laserdisc and key the text live to air in synch with the backgrounds. The segments are 30" in duration so that if a break was partially sold in a region, they would cut back to a beat-pause in the filler (assuming the ads sold were 30" long of course!)
There were breaks of various durations from 1'00 to 3'00 (4'00?), and there were also different combinations of News, Weather, Business etc some with/without certain segments so that if some of the data was out of date you could usually avoid a segment until someone at Ceefax could correct it. The Weather segment was often substituted for the News segment ISTR but wasn't in the main combinations of segments used by default, hence it's rather rare appearances on air.
If all else failed, you could choose to mask the incorrect bit of the break with a menu or if you were feeling very clever one of those moving flag segments from the other laserdisc.
Staggering the trouble we used to go to, to fill an unsold commercial break.
The ABF survived the 1999 rebrand in that Mac/Laserdisc form and provided break cover with the now infamous bit of David Lowe music that was released on CD. I was told that the 'Festival' BBC Prime rebrand and the 1999 BBC World rebrand used some of the very last blank laserdisc stock in the world (that could have been BBC Urban myth though). Eventually, something major broke in the ABF system (can't remember what but it may well have been the fact that Ceefax stopped providing Business, Weather & Sport content to BBC World teletext...) and we had to use a generic breakfiller for a while until the Dynamic Junction system was ready to air.
And if we thought the ABF could be prone to the odd wobbly, the DJ was a whole new story...