Looking out the large windows at my place of employment. Near the Rose Quarter. Windows face NE.At 11 am I saw what initially looked like a flock of birds but the proportions of the individual objects didn't appear to be birds after looking for another second or two. My boss was standing in front of me, talking to me, so I was trying to give my attention to her and to the objects.There were about 20-30, bright white, slightly silver, extremely reflective objects. About 300 feet from me, moving in my direction slowly, moving in a not-straight line. They were moving too uniformly compared to every other bird sighting I have seen. After about 5 seconds they flew out of range of the window. My boss was still talking to me so I couldn't run outside, but I knew I had seen something strange.At about 12:20, I happened to glance out the window again. Something reflective caught my eye, and after focusing in on it, I could tell it was the same objects I saw earlier. They were further away than before, maybe 6-800 feet (the opposite direction they were moving earlier), and were going in and out of transparency. They were in a tighter, more uniform formation, nearly spherical, but still seemed to float slowly this way and that, without a clear direction. I reached for my phone while keeping my eyes on them. They must've gone in and out of transparency 4 or 5 times in the 15-20 seconds I kept my eyes on them. I ran outside to get a shot and they were gone. This has left me very uneasy.After doing a little research, the closest comparison I can find is the youtube videos that show UFO 'fleets'. It is almost exactly like those except I only saw about 20-30 orbs and they definitely went in and out of transparency.