icons on the post thumbnails

I have to believe some custom CSS and conditional output would be best for you.

Borrowing heavily from googled images here.

Markup:

<div id="one">
  <div class="icon icon-foo"></div>
  <img src="http://i.ytimg.com/vi/kxMbTwEJbDU/hqdefault.jpg" />
  </div>
 
</div>
<div id="two">
  <div class="icon icon-bar"></div>
  <img src="http://i.ytimg.com/vi/kxMbTwEJbDU/hqdefault.jpg" />
</div>

Styles

.icon-foo {
  background: url('http://icons.iconarchive.com/icons/mazenl77/I-like-buttons-3a/256/Cute-Ball-Go-icon.png') 0 0 no-repeat;
  background-size: cover;
  position: absolute;
  height: 150px;
  width:150px;
}

.icon-bar {
  background: url('https://image.flaticon.com/icons/svg/579/579787.svg') 0 0 no-repeat;
  background-size: cover;
  position: absolute;
  height: 150px;
  width:150px;
}

Overall preview:

https://cloudup.com/cuqjSmdjvnX

The suffix for the .icon- classes could be which post type it is, and with each version intended defined in your css, it would conditionally match up like needed.

@reti just an idea of how you could potentially go about this, it’s by no means the *only* way to achieve this. See what you come up with and get creative.