We had these two Ailanthus altissima (tree of heaven) to do on friday, had one climber in each tree and two groundies chipping. No before pic sorry, just imagine about 4m of growth coming out of each of those 'knuckles'.
I kind of think of these as being 'scaffold pollards' where the main structure/framework of the tree remains and the previous 3 - 5 years growth is removed on a cyclical basis. The idea of this is to be able to maintain large full crowned trees safely in built up areas.
This is different to the agricultural pollards of old where only the main trunk would be kept and the cycle of cutting would be more like 10 - 15 years for trees where firewood/timber was the main incentive or every couple of years with willows etc when fodder/feed for animals was required.