When hanging from a building you need two lines. You are on an anchor (hopefully!), not a mountain- that means you need to follow OSHA procedures, especially if you’re in front of an employee or if you are posting it as an example online. Building owners get fined too, even if you are not an employee.
You should be on two anchors at least, each line being independently anchored.
Other would-be high rise window cleaners need good role models. People die because of using only one line.
A word of caution for this particular five story job: There may be anchors, but are they for chair work? They could be for walking the roof or for stage work.
If there are gutters, I don’t see the anchors being for chair work.
Do they have paperwork for the anchors, telling you when they last have been inspected?
Perhaps u already know these issues…