Discovery API supports specifying a tile in a URL.

chrome/browser/extensions/api/discovery/suggested_link.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_BROWSER_EXTENSIONS_API_DISCOVERY_SUGGESTED_LINK_H_
 #define CHROME_BROWSER_EXTENSIONS_API_DISCOVERY_SUGGESTED_LINK_H_
 
 #include <string>
 #include <vector>
 
 #include "base/memory/linked_ptr.h"
 
 namespace extensions {
 
 // ExtensionSuggestedLinks contains a list of scored links that the extension
 // wants to inject in the NTP's recommended pane.
 class SuggestedLink {
  public:
-  SuggestedLink(const std::string& link_url_, const std::string& link_text_,
-                double score);
+  SuggestedLink(const std::string& link_url, const std::string& link_text,
+                const std::string& url_image, double score);
   ~SuggestedLink();
 
   const std::string& link_url() const { return link_url_; }
   const std::string& link_text() const { return link_text_; }
+  const std::string& url_image() const { return url_image_; }
   double score() const { return score_; }
 
  private:
   std::string link_url_;
   std::string link_text_;
+  std::string url_image_;
 
   // |score_| is a value between 0 and 1 indicating the relative importance of
   // this suggested link. A link with score 1 is twice as likely to be presented
   // than one with score 0.5. Use a score of 1 if no information is available on
   // the relative importance of the links.
   double score_;
 
   DISALLOW_COPY_AND_ASSIGN(SuggestedLink);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_DISCOVERY_SUGGESTED_LINK_H_