Or a snowy egret but hard to tell which it is without them standing side by side. There's only a very slight difference in height.
Regardless, nice capture and good job on the whites.
I think you are right K9. One of the main differences is in the colour of the "Lore" and the eyes apparemtly, which are paler in the little Egret by comparison with the Snowy White. These are quite a pronounced yellow in Mitch's image.