When picking assets from the object picker window, the transition between different asset preview sizes is not smooth. When the preview is resized and a different asset preview is needed (e.g. changing from a small icon to large icon), two instances of the asset will be shown in the panel together for a second or so.

1. Open Unity
2. Open the attached project
3. Select the "Sprite" gameobject from the hierarchy
4. In the Sprite Renderer component in the inspector, open the object picker via the Sprite property
5. Highlight any asset and size the asset preview panel up and down

Expected Result:
When the panel transitions between different preview sizes, the old preview disappears immediately and the new one is shown.

Actual Result:
When the panel transitions between different preview sizes, two instances of the asset preview are shown temporarily.

Tested on Windows.

Occurs on 2019.3.0a8, 2019.2.0b7, 2019.1.9f1, 2018.4.3f1, 2017.4.29f1