I can't show the icon of my application in iTunes - ios

Question

I make an iPhone application and my customer want to see that. So I created a ipa file, but there is no icon :
I don't understand because on the iPhone there is no problem :
Would I forget a picture format?
For info, this application is not on the App Store now. It's only for the customer and for my boss (they need to check).
Thank You!
--- Edit:
Thank you for your many reply but after message of #Vakas I add iTunesArtwork and iTunesArtwork#2x, two png files without extension like this (but no effect):
config.xml:
<?xml version='1.0' encoding='utf-8'?>
<widget android-versionCode="15" id="com.ionicframework.test5119111" ios-CFBundleVersion="8.4" version="0.0.1" xmlns="http://www.w3.org/ns/widgets" xmlns:cdv="http://cordova.apache.org/ns/1.0">
<preference name="AllowInlineMediaPlayback" value="false" />
<preference name="BackupWebStorage" value="cloud" />
<preference name="DisallowOverscroll" value="false" />
<preference name="EnableViewportScale" value="false" />
<preference name="KeyboardDisplayRequiresUserAction" value="true" />
<preference name="MediaPlaybackRequiresUserAction" value="false" />
<preference name="SuppressesIncrementalRendering" value="false" />
<preference name="GapBetweenPages" value="0" />
<preference name="PageLength" value="0" />
<preference name="PaginationBreakingMode" value="page" />
<preference name="PaginationMode" value="unpaginated" />
<feature name="LocalStorage">
<param name="ios-package" value="CDVLocalStorage" />
</feature>
<feature name="Keyboard">
<param name="ios-package" onload="true" value="IonicKeyboard" />
</feature>
<feature name="Console">
<param name="ios-package" value="CDVLogger" />
</feature>
<feature name="Device">
<param name="ios-package" value="CDVDevice" />
</feature>
<preference name="AndroidPersistentFileLocation" value="Internal" />
<feature name="File">
<param name="ios-package" value="CDVFile" />
<param name="onload" value="true" />
</feature>
<feature name="FileTransfer">
<param name="ios-package" value="CDVFileTransfer" />
</feature>
<feature name="SplashScreen">
<param name="ios-package" value="CDVSplashScreen" />
<param name="onload" value="true" />
</feature>
<icon height="57" src="resources/ios/icon/icon.png" width="57" />
<icon height="114" src="resources/ios/icon/icon#2x.png" width="114" />
<icon height="40" src="resources/ios/icon/icon-40.png" width="40" />
<icon height="80" src="resources/ios/icon/icon-40#2x.png" width="80" />
<icon height="50" src="resources/ios/icon/icon-50.png" width="50" />
<icon height="100" src="resources/ios/icon/icon-50#2x.png" width="100" />
<icon height="60" src="resources/ios/icon/icon-60.png" width="60" />
<icon height="120" src="resources/ios/icon/icon-60#2x.png" width="120" />
<icon height="180" src="resources/ios/icon/icon-60#3x.png" width="180" />
<icon height="72" src="resources/ios/icon/icon-72.png" width="72" />
<icon height="144" src="resources/ios/icon/icon-72#2x.png" width="144" />
<icon height="76" src="resources/ios/icon/icon-76.png" width="76" />
<icon height="152" src="resources/ios/icon/icon-76#2x.png" width="152" />
<icon height="29" src="resources/ios/icon/icon-small.png" width="29" />
<icon height="58" src="resources/ios/icon/icon-small#2x.png" width="58" />
<icon height="87" src="resources/ios/icon/icon-small#3x.png" width="87" />
<icon height="512" src="resources/ios/icon/iTunesArtwork" width="512" />
<icon height="1024" src="resources/ios/icon/iTunesArtwork#2x" width="1024" />
<splash height="1136" src="resources/ios/splash/Default-568h#2x~iphone.png" width="640" />
<splash height="1334" src="resources/ios/splash/Default-667h.png" width="750" />
<splash height="2208" src="resources/ios/splash/Default-736h.png" width="1242" />
<splash height="1242" src="resources/ios/splash/Default-Landscape-736h.png" width="2208" />
<splash height="1536" src="resources/ios/splash/Default-Landscape#2x~ipad.png" width="2048" />
<splash height="768" src="resources/ios/splash/Default-Landscape~ipad.png" width="1024" />
<splash height="2048" src="resources/ios/splash/Default-Portrait#2x~ipad.png" width="1536" />
<splash height="1024" src="resources/ios/splash/Default-Portrait~ipad.png" width="768" />
<splash height="960" src="resources/ios/splash/Default#2x~iphone.png" width="640" />
<splash height="480" src="resources/ios/splash/Default~iphone.png" width="320" />
<name>test5</name>
<description>
An Ionic Framework and Cordova project.
</description>
<author email="hi#ionicframework" href="http://ionicframework.com/">
Ionic Framework Team
</author>
<content src="index.html" />
<access origin="*" />
<preference name="orientation" value="portrait" />
<preference name="HideKeyboardFormAccessoryBar" value="true" />
<preference name="AndroidPersistentFileLocation" value="Compatibility" />
<preference name="iosPersistentFileLocation" value="Library" />
<preference name="iosPersistentFileLocation" value="Compatibility" />
<preference name="AllowInlineMediaPlayback" value="true" />
<preference name="android-minSdkVersion" value="14" />
<preference name="webviewbounce" value="false" />
<preference name="UIWebViewBounce" value="false" />
<preference name="DisallowOverscroll" value="true" />
<preference name="android-minSdkVersion" value="16" />
<preference name="BackupWebStorage" value="none" />
<preference name="SplashScreen" value="screen" />
<preference name="SplashScreenDelay" value="3000" />
</widget>
folder:
Maybe it's the same thing like this topic : http://muaca.blogspot.jp/2015/10/cordova-development-ios-itunesartwork.html
But there is not the "devise" folder like them example :
/mobile_app_root/platforms/ios/build/device/generated-app.app
This is my folder:

Answer 1

You’re missing an icon for AppStore with a resolution of 1024 x 1024. Please add that it will show up in the iTunes.

Answer 2

You must add the images with the name:
"iTunesArtwork" (.png, without extension, 512x512) and
"iTunesArtwork#2x" (1024x1024) in the project.