Repro steps:
1. Open Scene1 from attached project.
2 In the Hierarchy, expand the canvas so Image A and Image B can be seen.
3. Select Image A and ctr-select Image B
4. Notice how Image A changes to match Image B (their fill origin gets set to Right)

Note:
- The Inspector tab must be visible for the issue to occur.
- Not a regression, happens in 5.5.0f3
- Might be related to case 819441 (though their sets it to the left and the bug has not been processed)