We included it since just looking at the source you probably want to know which build it comes from. Originally it was just going to be in that column, but that value is not sortable or searchable in the source column so we added the build column separately so you can sort and search over them.
Its probably somewhat redundant to have both places but we figured it would be nice to have visibile at all times while also being able to sort and search over it. Thanks for the question!