Currently, if you use an asset in Studio (eg: a PNG image), and then make some changes to the asset, and save over the file used by Studio, Studio will continue to display the 'old' version of the asset until the Page is closed and re-opened.

Video attached.

Repro Steps:

1) Prepare any PNG image of your choice.
2) Create a Studio Project featuring a MainPage.xaml, and place the image from Step 1) inside of the Project directory.
3) Introduce the image to the Page by dragging-and-dropping it from the Assets Panel into the Root Grid.
At this point, the image will display on-Stage.

4) Open the image asset used by Studio in any image editor (Paint works great), make any visible changes to it, then save over it.

5) Open the image asset in Windows Photo Viewer, or any other image-viewing application.
Observe how the changes made in Step 4) are present on the asset.

6) Open Studio, and view MainPage.xaml.
Observe how the asset present on the Page is not correctly showing a reflection of the asset its supposed to be using.

7) Close the Page, and re-open it.
Observe how now, the Page displays the correct version of the image asset.

Expected Results: Studio always displays a real-time representation of the current asset saved on-disk.