Message window appearance

Hello! I have a question about the message window appearance. In my layout the message window is below the message list. Is it possible to make the message header smaller? I am referring to the part in a red frame in the example. It takes a lot of space and I need to scroll down the window to see more content. I tried to remove the avatar from this part, but it doesn’t seem possible. I would prefer a more compact appearance of this section, without avatar and with smaller distances between the lines (From and To could be directly under the Title). Or maybe it is possible to remove/hide this section completely? When I select a message in the list, I already know the sender, the title and the date anyway so there is no need to repeat this information. Please advise.