If used in a lantern tool post in the normal fashion, the head could swivel in conjunction with the tool post rocker to attain center height and parallelism between the spindle axis and the boring bar.
I have a similar boring tool holder made by the Bokum Boring Tool Co. that achieves this with a adjustable clamped vertical dovetail joint between the shank and the tool holding bore. It is to my eye, a boring tool holder.
The swivel at the head allows you to make all 3 adjustments in a lantern type tool post. If it was fixed, it would be for a QCTP. With the swivel head it can be used anywhere... looks like a nice piece of kit.
Here are some pics of the similar tool that I talked about in my earlier post; this holder adjusts vertically to adjust the boring bar to center height, made by Bokum Tool Co. takes 1/2" shank tools, with apologies to them, not one of their boring tools pictured in it., their tools are form ground, and are only sharpened on top, and have a back rake, and cut very freely, they come in several styles, including lead angle, flat bottom, threading, chamfering and grooving, from tiny to big.