Well for starters it is off season so any pictures are of short run jumps and drills that would use smaller poles, and a lot of vaulters use really soft squishy poles for short run drills.
But if you have ever seen Lavillenie pole vault you will quickly learn he typically bends the pole much more than other vaulters. There are several factors that influence this. I think the biggest reason is he is shorter so to use just as long of pole as the taller vaulters he must compress his poles more to get them to roll over into the pit. But he is also much faster than most vaulters so he is not just using a soft pole, those are large poles he is crushing. But he also takes of 'on' running very fast and what appears to be some what flat. But it is not because he can not jump because if you have seen his heptathlon results he can long jump over 24'.
When it comes down to it I think he just runs as fast as he possibly can, plants the pole, and goes for it. Then gets launched like a cannon off the top.
Would I teach this to a brand new high school vaulter? No. But if I had a college vaulter jump like him and do well would I change it? Probably not.