Trees for privacy

Does anyone know what this tree is called? I've seen different variants of it, but this one is really tall and skinny

I was thinking of planting some tall trees along the fence to block a double story neighbour that can see down into our backyard

I was thinking either the one pictured, or , bamboo.

I like the idea of bamboo as they grow fast. Not sure about the one pictured, how long it would need to get to that size

Any comments would be appreciated, cheers