It looks like a Salix, but not sure which one without seeing the leaves in more detail.

yes it does look like a Salix.

I agree a salix and it looks to be planted too close to the fence.

There are different varieties of very varying sizes too.

Probably salix flamingo or hakuru nishiki ,as it's grafted only the top growth will get bigger but can easily be pruned in early spring to encourage the colourful new growth.