update viewer

[meganrm]

Pull request recommendations:

• Name your pull request your-development-type/short-description. Ex: feature/read-tiff-files
• Link to any relevant issue in the PR description. Ex: Resolves [gh-##], adds tiff file format support
• Provide description and context of changes.
• Provide relevant tests for your feature or bug fix.
• Provide or update documentation for any feature added by your pull request.

Thanks for contributing!