Are you talking about having Asciidoctor style each HTML element individually
inline for the whole document?
Not just one element
image:diagram.png[Diagram,150,150,float="right"]
which renders the style inline in the span.
<p>
<span class="image" style="float: right">
<img src="diagram.png" alt="Diagram" width="150" height="150">
</span>
</p>