Showing file title in App Expose

There are some files when I mouse over it in the App Expose highlights it and show the file title and some doesn't display the file title.

It is faster and better for me if it the file title shows up on mouse over as the wallpaper I had made the file title very hard to read even though it it at the bottom of the thumbnail.

Is there a way for me to make sure the file title shows up on mouse over?

Since it does for some and not for others I assume it is doable but I might have done something wrong?

All the documents are in the same folder and are viewed by Preview.

I have a 2015 13" MBP running the latest ElCap. The computer is pretty vanilla without much apps or 3rd party tweaks as I am treating this as a pure productivity machine.

Here are some pictures illustrating my point