Hi Mideum Jo,
As per the Image Viewer Docs,
"The Dynamic Image widget, which is not supported by the React client added to Mendix in 10.7, can be converted to an Image widget through the context menu of the widget when the React client is enabled.".
So, the Image widget is the way to go.
You can also check this Medium post about the topic.
Please accept this answer if it helped,
Best regards,
João
In order to be able to use old widgets (Dojo widgets), you can set the "Use React Client" setting to "No" or "Migration Mode".
You can change this setting from: App Settingz -> Runtime