Different image content copied from clipboard saved as same media item

Description

Steps to reproduce

1. Edit an XhtmlString property using the TinyMce editor.
2. Capture an image (Image1) to the Clipboard (e.g., open an image file in Paint then copy its content).
3. Paste the image into the TinyMce editor > A new media item is created with the default name "image.png".
4. Repeat steps 2 & 3 above for another image (Image2).

Expected:
Create new media item of Image2.

Actual:
Replace image.png media version (Image1 -> Image2).

Observed: Testing results in standard editor of TinyMce 4.8.2 via https://www.tiny.cloud/docs/demo/full-featured/ as below.
1. When copy & paste the same image content, it results the same Blob image's GUID in img src URL.
2. When copy & paste different image content, it results different Blob image's GUID in img src URL.

  <img src="blob:https://s.codepen.io/71f0c448-da0a-43e1-86f3-b322d9c4d1ba" width="187" height="187" />
  <img src="blob:https://s.codepen.io/71f0c448-da0a-43e1-86f3-b322d9c4d1ba" width="220" height="220" />
  <img src="blob:https://s.codepen.io/f803a890-1cb4-4ff2-be9f-acf8b2ec1762" width="199" height="124" />