Embedded into NuGet package icon doesn't appear in VS

I generate a nuget package using my nuspec file below:

<?xml version="1.0" encoding="utf-8"?><package ><metadata><id>CommonLib</id><version>1.2.3</version><authors>ABC</authors><owners>ULC</owners><requireLicenseAcceptance>false</requireLicenseAcceptance><license type="file">Licenses\License.txt</license><icon>Icons\Icon.PNG</icon><description>Common References</description><copyright>Copyright (c) 2020</copyright><tags>Common</tags><dependencies><group targetFramework="net48" /></dependencies></metadata><files><file src="lib\net48\Common*.dll" target="lib/net48" /><file src="Licenses\License.txt" target="Licenses\" /><file src="Icons\Icon.PNG" target="Icons\" /></files></package>

The folder structure for the source data for packing is as the following:

RootDir    Icons        Icon.png    lib        net48            Abc.dll            Common1.dll            Common2.dll            xyz.dll    Licenses        License.txt    My.nuspec

I successfully generate it. However, whether I host it locally or in my Azure Artifacts as private feed, then when I browse in VS2017 (that's what I currently have installed) to install for a project then the generated package doesn't show its embedded icon, instead, it shows the default nuget pack icon. I tried browsing either from my local feed or from Azure private feed, same thing. What's the reason my embedded into nuget pack icon is not being used?