Diamond and "mi" note heads

I've been trying to figure out the difference between these two note heads. In the "Note Heads" palette, the note head that says it's a "half diamond head" doesn't at all look like the kind of diamond note head I'm looking for. In fact, the "mi" note head looks exactly like the one I'm looking for, however it does not specify it as a diamond note head.

My question is what is the "half diamond head" suppose to be for? It doesn't look like any note head I've seen before. I can't even find that specific note head style when I try to search for it.

And before I'm told of an easy way to get around it, yes I know I could just use the "mi" note head and not worry about it, but this is also a chance to figure out more about Musescore, and if this was intentional.