I worked along side some of the best terrazzo men in my time, and that vid was spot on , as far as the fixing method was concerned, but it was a patch up job. A good terrazzo man can lay 100m2 per day, every day, a good labourer is essential imo. The method is the same on a new floor. A leg is brought from the first course,laid perfectly straight and level, then a tingle line is fixed, so you repeat again and again. The method is tried and tested, as we have said the subfloor is given a slurry bond coat, ( traditionally pure portland cement) then semi-dry mix 4:1 sand and cement. then either a slurry bond over the semi-dry mix, or the back of the tile brushed with slurry.
All the terrazzo men I know never kneel down, but fix from a standing position.The old polishing machines were called Ellis, the newer ones are Terrco's. The polishers job is made easy or hard by the skill of the fixer. Hope I don't get a lashing from the terrazzo lads who are more up to date than me.