@Bo Jacobsen Probably I did not wrote the question right. I have block list with elemnt inside which elemnt contain one property media picker in the preview I set div tag to show me the object which I get from block.data and the media item has only 4 properties the two of them was key mediaKey and the others was type or smth like that

Okay, you need to make your own preview controller and get all the data you need and display.

A better description is here https://our.umbraco.com/Documentation/Fundamentals/Backoffice/property-editors/built-in-property-editors/Block-List-Editor/

// Preview html
<div ng-controller="customBlockController" ng-click="block.edit()">
    <h2 ng-bind="block.data.headline"></h2>
    <img src="{{imageUrl}}" />
    <p ng-bind="block.data.description"></p>
</div>

// Preview Controller
angular.module("umbraco").controller("customBlockController", function ($scope, mediaResource,imageUrlGeneratorResource) {

    //your property is called image so the following will contain the udi:
        var imageUdi = $scope.block.data.image;
    //the mediaResource has a getById method:
        mediaResource.getById(imageUdi)
            .then(function (media) {
                imageUrlGeneratorResource.getCropUrl(media.mediaLink, 150, 150).then(function (cropUrl) {
                console.log(cropUrl);
                $scope.imageUrl = cropUrl;
            });
    });    
});

// Preview package.manifest
{
  "javascript": [
    "~/App_Plugins/CustomBlockView/customBlock.controller.js"    
  ]  
}