Admonitions ignore aligned figures

Problem

The box for the admonition is not giving way to an aligned image that has less than full width.

Reproducible Project

Project is here. Page shown in screenshot is live here.

Section shown in attached screenshot:

.. |nsp| unicode:: 0x200B
   :trim:

.. _chapter:guidelines:

Rendering Guidelines
====================

.. _section:basicscene:

Basic scene anatomy
-------------------

.. figure:: image/basic_scene_anatomy.svg
   :alt: The fundamental building blocks of an nsi scene
   :align: right
   :figwidth: 45%

   The fundamental building blocks of an nsi scene

A minimal (and useful) nsi scene graph contains the three following
components:

#. Geometry linked to the ``.root`` node, usually through a transform
   chain.

#. OSL materials linked to scene geometry through an node.

#. At least one *outputdriver* |nsp| → |nsp| *outputlayer* |nsp| → |nsp|
   *screen* |nsp| → |nsp| *camera* |nsp| → |nsp| ``.root`` chain to
   describe a view and an output device.

The scene graph in shows a renderable scene with all the necessary
elements. Note how the connections always lead to the ``.root`` node. In
this view, a node with no output connections is not relevant by
definition and will be ignored.

.. Caution::
   For the scene to be visible, at least one of the materials has to be
   *emissive*.

Results

Expected Results

The bar should be cut by the image/figure. Note that the text in the admonition bar is actually affected by the image/figure, only the bar itself isn't.

Environment Info

• Python Version: 3.7.6
• Sphinx Version: 2.3.1
• RTD Theme Version: live version