Intelligence Reports uses a different measurement for In-App Displays than Journey Builder with Displayed.
For In-App Displays, this metric counts the number of displays per device regardless of whether the receiving contact has interacted with that display, such as through a click or dismiss.
For Displayed, this metric refers only to displays that the receiving contact has interacted with in some way, such as through clicking or dismissing.
When comparing Intelligence Reports and Journey Builder Analytics for In-App sends, it would be better to use the sum of In-App Device Button Clicks + In-App Device Dismisses to achieve the result Displayed in Journey Builder.
Dimensions and Measurements in Intelligence Reports:
https://help.salesforce.com/s/articleView?id=mktg.mc_dat_dimensions_and_measurements.htm&type=5
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