Unknown Object Ascending and Flying Over The CityScape Building in Downtown Phoenix

Just to be clear, I am not referring to the light bar reflection in the window.
I have been in this office for a number of years now, and this is the first thing I have spotted in this area.
From my perspective, when I looked out the window, it was my impression that this object came off of the roof of the brown building, which is The Luhrs Building in Downtown Phoenix, not to be confused with The Luhrs Tower, which is on the same block. I also looked it up, and The Luhrs Building is approximately 140 feet tall. I did not see the object in a landed position, but first noticed it as it rose up from what I perceived to be the roof.
As it was flying upwards, I thought it would be a good idea for me to pull my Iphone out and record it. The beginning of the video is me attempting to find the object on my screen. I did not specifically see whether the object made a 90-degree turn once it hit a certain height, but the fact that it rose straight up, to then go over the nearby building makes me think it was likely a perpendicular turn.
The nearby black building that you can also see in the video, in which the object flew, seemingly, just slightly over it, is called The CityScape Residences Building. I looked it up, and that building is approximately 300 feet tall. Note that these building are on opposite sides of the same street so they are not right next to each other.
So, this object rose up 150 feet before making what appears to have likely been a perpendicular turn, to then fly east or possibly slightly northeast over the nearby building.
I will attach the raw video from my Iphone, and some zoomed in screenshots from the video. I have other videos that give some perspective and some other screenshots, but I can see your system only allows for uploading five files. I can provide those other files later if you like.
I do not know what this is, but I can say they are not bags, balloons, or a drone. I have seen all three of those objects from the same location, at a farther distance, and can clearly identify those objects.
I also sent this footage to The Aerial Phenomenon Investigations Team, and they did a really nice breakdown and enhancement, which can be seen on their Youtube Channel here: https://youtu.be/VaekfsiN_qU 
What I only recently realized upon reviewing the enhanced video, that one of the interesting aspects happens right at the end, the last few seconds, where I kept recording, even though I could no longer see the object. The object rushes into the air, before dropping pretty substantially, all without any sort of spreading or burst of light that would be expected if this was mylar balloons.
I am still in the office space, if someone did want to come by to gain perspective on what I observed.