We can tell most everything we need to from the angle requested, but this angle leaves some things out. Like stance width and bar position and grip. All of which are helpful. Which is why we ask for the angle.
You're trying to avoid actually getting your chest at the ground, and are over extending the low back as you start so it's a wiggly mess through the set. A belt would help. Also, drop your eyes to about 1.5m in front of you on the ground and keep them there.