1. Mechanism of highlighting popup's selected feature from a query enabled map image layer? Found the popup highlighting is enabled by default for feature layers, controlled by view.highlightOptions. Is there a magical setting for map image layer then there is no need to have a workaround using graphics?
2. For the feature layer popup highlighting, where is that piece of blue highlighting graphic stored in JS? Initially, I thought it may be in view.graphics, not there.
Side by side comparison:
Map Service, popup and no highlighting: Highlight popup on MapImageLayer - ArcGIS JS API 4.9
Feature Service, popup and highlighting in blue: Highlight popup on FeatureLayer - ArcGIS JS API 4.9
Appreciated if there is anyone with such experience.