i honestly dont think it does anything. ive never noticed it before but i cant think of anything that would be behind that that it would hold or anything
I have nothing technical to add, but that is a thing of beauty.
All I can think of is maybe it was used as a fluid level sensor (but it seems kinda high for that), or it was used as a mounting location for a wiring bracket.
Check my avatar and you will see where these ideas are coming from.