Are people not looking at the photo?
There are bricks that are entirely beyond the string, and gaps of fresh air below it. It's crap.
No idea why the pointing's missing either, filling it in after will be vastly weaker than doing it right in the first place. It's basic brickwork stuff, there should be a bit too much mortar, which you then tool off. There may be the of tiny bit of a perp that needs gobbing up while pointing, but it all gets done at the same time. There are lengths of bed joint that aren't there. Most perp joints must be mostly empty. I'm an utterly amateur DIY brickie but I'd give up if my work looked like that.