I want to append image to string/text while writing service

Please check below service code:

var connections;

if (filter == "blank") {

  connections = Networks['FlowServeNetwork'].GetNetworkConnectionsWithTemplate();

} else {

  var params = {

  start : filter

  };

  connections = Networks['FlowServeNetwork'].GetSubNetworkConnectionsWithTemplate(params);

}

var params = {

  dataShapeName : "FlowserveTreeNetwork",

  infoTableName : "AssetHierarchy"

};

// CreateInfoTableFromDataShape(dataShapeName:STRING, infoTableName:STRING("")):INFOTABLE

var assets = Resources['InfoTableFunctions'].CreateInfoTableFromDataShape(params);

var connection;

for each(connection in connections.rows) {

  var data = new Object();

  data.to = connection.to;

  data.from = connection.from;

  data.connectionType = connection.connectionType;

  var thing = Things[connection.to];

  var alert = MediaEntities["YellowAlert"].GetImage();

    data.description = thing.description + " " + alert; //appending alert icon with description

    assets.AddRow(data);

}

var result = MediaEntities["YellowAlert"].GetImage();

----

am unable to append image with text. I have tried keeping description type as text,blob,string in datashape.

am getting error as "[context: com.thingworx.webservices.context.HttpExecutionContext@2ea80460][message: Execution error in service script [FlowserveNetworkServices testImage] : Unable To Convert From [B to INFOTABLE]"