I have designed an Adaptive card and it is rendering fine. I also have a Action.ShowCard type button which also has an Adaptive card. Any image in the main card is showing perfectly but if I place any image in the Adaptive card of the Action.ShowCard it is rendering like this 
The image shows as undefined. Also in the HTML the image tag has no src
Info
The image url is public and is showing perfectly in the main card but not in the show card
I tested it using the
App Studio's UI Tooland it is also giving the same error
{
"type": "AdaptiveCard",
"$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
"version": "1.2",
"body": [
],
"actions":[
{
"type": "Action.ShowCard",
"title": "Action.ShowCard",
"card": {
"type": "AdaptiveCard",
"$schema": "http://adaptivecards.io/schemas/adaptive-card.json",
"version": "1.2",
"msteams": {
"entities": []
},
"body": [
{
"type": "ColumnSet",
"columns": [
{
"type": "Column",
"width": "auto",
"items": [
{
"type": "Image",
"url": "https://upload.wikimedia.org/wikipedia/commons/thumb/b/b6/Image_created_with_a_mobile_phone.png/1200px-Image_created_with_a_mobile_phone.png",
"size": "Small"
}
]
},
{
"type": "Column",
"width": "stretch",
"items": [
{
"type": "TextBlock",
"text": "Color theorysdjkf",
"wrap": true,
"weight": "Bolder",
"color": "Attention"
}
],
"verticalContentAlignment": "Center"
}
],
"height": "stretch",
"horizontalAlignment": "Center",
"separator": true,
"spacing": "Large"
},
{
"type": "TextBlock",
"wrap": true,
"spacing": "Small",
"text": "You selected **A**"
},
{
"type": "ColumnSet",
"columns": [
{
"type": "Column",
"width": "stretch",
"items": [
{
"type": "TextBlock",
"wrap": true,
"text": "This is a long explanation for the answer and I think it is getting so long and long and long long long long "
}
]
}
],
"style": "emphasis",
"spacing": "Small"
}
]
},
"style": "positive"
}
]
}