I assume it will behave the same way as doing a dual display from your laptop (e.g. laptop LCD, and projector). When you do this sa laptop, it will take the lower resolution, and use that for both displays (so normally, yung laptop LCD is shown at a lower resolution).
Again, assumption lang 'to, as I don't have experience on HDMI splitters.
If this assumption is correct, then it will mean na 2-way siya. It uses the lowest resolution of all displays.