It looks like it started out as a sword sucker but, like the previous posters mentioned, the mother is not established enough yet for it to produce a sucker that retains sword leaves for any notable period of time before becoming a normal water sucker type stem. That being said, there is absolutely nothing wrong with leaving it on the plant, provided it's being fed enough or the soil is rich enough to support the plant properly. As many experts on here have said, there is no difference between the growth of a sucker that started out as a sword and one that started out as a water after a few weeks to months. So, you don't have to cut it out feeling as though it's "useless". I have a couple of my own bananas that pushed out only water sucker initially and those grew fine. Just wanting to throw that out there
