How can WhatsApp show me an image\video if I didn't download it to phone? [Solved]

If I send an image\video via WhatsApp and the other person didn't download it, how can he still see the image as a blurry image?

From looking through the app's database I found out that the local path of the image that was downloaded is located in thumb_image column in messages table. However if the image is not downloaded I don't have any information about the local path.

Does WhatsApp stores that image as temporary image data on the device?
Thumbnails are stored in WhatsApp's database as BLOB in the message_thumbnails table, under thumbnail column.