However, in Home Assistant (https://www.home-assistant.io/integrations/joaoapps_join/), the Join Notify service allows for the creation of both a "smallicon" and an "icon" (similar to a contact profile image in a whatsapp notification) :
The Join component in HomeAssistant does not seem to be an official one from JoaoApps, but I can't see a reason why this "icon" feature wouldn't be available in Tasker too ?
Here is the error message :
Join - java.lang.RuntimeException: Unable to start activity ComponentInfo{com.joaomgcd.join/com.joaomgcd.join.tasker.activity.ActivityConfigSendPush}: java.lang.IllegalStateException: ListPreference requires an entries array and an entryValues array.
com.joaomgcd.join version 2.2
Source com.google.android.packageinstaller
OS Build ONEPLUS A5000_23_180129
OS Code 26
Device ONEPLUS A5000
Manufacturer OnePlus
Product OnePlus5
java.lang.RuntimeException: Unable to start activity ComponentInfo{com.joaomgcd.join/com.joaomgcd.join.tasker.activity.ActivityConfigSendPush}: java.lang.IllegalStateException: ListPreference requires an entries array and an entryValues array.
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2946)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3046)
at android.app.ActivityThread.handleRelaunchActivity(ActivityThread.java:4958)
at android.app.ActivityThread.-wrap18(Unknown Source:0)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1694)
at android.os.Handler.dispatchMessage(Handler.java:105)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6809)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
Caused by: java.lang.IllegalStateException: ListPreference requires an entries array and an entryValues array.
at android.preference.ListPreference.onPrepareDialogBuilder(ListPreference.java:249)
at android.preference.DialogPreference.showDialog(DialogPreference.java:306)
at android.preference.DialogPreference.onRestoreInstanceState(DialogPreference.java:453)
at android.preference.ListPreference.onRestoreInstanceState(ListPreference.java:315)
at android.preference.Preference.dispatchRestoreInstanceState(Preference.java:2034)
at android.preference.PreferenceGroup.dispatchRestoreInstanceState(PreferenceGroup.java:329)
at android.preference.PreferenceGroup.dispatchRestoreInstanceState(PreferenceGroup.java:329)
at android.preference.Preference.restoreHierarchyState(Preference.java:2016)
at android.preference.PreferenceActivity.onRestoreInstanceState(PreferenceActivity.java:1041)
at android.app.Activity.performRestoreInstanceState(Activity.java:1070)
at android.app.Instrumentation.callActivityOnRestoreInstanceState(Instrumentation.java:1280)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2919)
... 10 more