Flashing Question

I think you’re right.

Flashing for weep…not after the fact…which is what that looks like…but then again Im not there…limited pictures yield limited information and opinion.

Is there a chimney behind that shoulder bump out?
IMO It was an ideal not fully developed.

SUSPECT.The flashing for the bump-out.

It is called the chimney shoulders.
You see the when the chimney is on the exterior.

Is it am insert firebox?

Look at the masonry connection that ties into the wall.
The masonry is lose,** Call it out.** Bad areas. It will effect the inter. Hope it is not an insert.
The top of the (shoulder) should be one piece stone to reflect the moisture and weather.
It should be inserted to the back of the first course of brick.
I see it in brick everywhere I go now.
The stone should over hang the shoulders on all sides and have a rain curf.
JMO.
Sorry I did not read all the posts.

They are picking up any water/moisture above that fireplace and shedding it on either side.
That is the shoulder of the chimney . Could be a smoke shelf of just a wide base to stabilize the unit.

Nope, no chimney. That’s the way all gas fireplaces are done here. You can see the vent in the first pic.

Sorry John.
Christ when you look at the photo you can plainly see a frigged window where the stack would be. HA HA Every thing but the bump-out and flashing remained when I enlarged the image to see the masonry detail.

John; it is a bricked protrusion being used to insert a fire box and vent out hot gases.
I will see if it can be classified as a chimney element.

SUSPECT: Failed masonry. Vertical masonry cracking on the angled brick course. The start of the bump-out for the insert.
RECOMMEND: 1.) (point) Redo the masonry 3 courses above and below including effected are.
Insure the mason can match the color.
2.) a. Flashing the angle. or b. Flash the shoulder.

Thanks John.