I don't know exactly why this clover is behaving this way, but it is interesting. Clover flowers open from the bottom up, so for some reason this one has just continued to grow and produce more flowers at the tip. It is quite possibly a natural mutation, if that is the only one you see around. It is also possible that it is an example of fasciation https://hort.extension.wisc.edu/articles/fascinating-fasciation/. This is caused by an insect, bacteria, or any of several other things, and usually results in a flattened, elongated stem with far more flowers than usual. This clover doesn't appear flattened or distorted, but that is still a possibility.
If you like it, try digging a piece of that plant up and planting it elsewhere, to see if the behavior continues next year.