Guys, the signal is called an "Approach Distant" and is used to tell the train crew of an approaching interlocking/signal. The signal is fixed to display just the yellow indication.
There are a few of these up in Indiana. They do come in various shapes and sizes.
The blade is just merely a representation, as the yellow bowtie and light are enough. Some plates have a yellow plate with a D for "Distant".
So there should be atleast a signal ahead. These are most common on branches and unsignaled mainline when approaching signaled territory.
The territory I worked had 3 type. Semaphore, Signal, and banner.