Lemonator is awesome. It is however, not a cleaning agent. It is a surfactant. And very slick one. I had a drum spout start leaking in the shop over July 4th weekend and about 30 gallons pooled out across my shop. Lot's of oil dry down and sticky boots.
The owner stated another pressure cleaning company tried last year and couldn't get the spots removed. Not sure if it was small time big box store guy or what. But I think good dwell and some pressure it should come up.
I would shoot SH on it with a pump sprayer. Add a bit of Elemonator. Be sure to hydrate all of the plants and the windows before and after application.Let the solution dwell for about 10-15 minutes and rinse with a second story tip.Note: Try a small spot first to see if it works and doesn't discolor the white brick.
Just mildew. SH. Might need more than one pass, but it'll clean it. On all brick, stucco, and dryvit we X-jet. You'll be there a month of sundays trying DS SH on that and expect it clean.