I have a blog where all articles in the front page are displayed in a masonry layout, with a thumbnail and a title beneath it. And you have to click them to read.
Now, sometimes I blog about videos, and I thought I should add a play-button image or a youtube logo onto the thumbnails. I thought this would be a good idea because then users can differentiate between the articles, which ones are "normal/text" articles and which ones are videos.
I've seen some sites do this, but for some reason the major sites do not. Examples are Buzzfeed again and Huffingtonpost. You can't tell which of their articles are just text/pictures or videos. Why is that?