Yeti,
Person A
Squats:
- Knees travel forward a tad at bottom
- Back extension loosens at bottom
- Don't slow down at the bottom, you lose the "bounce" from the natural stretch reflex
Overall definitely good I think, is this a beginner? If so it's very good. Depth is good, there's hip drive, elbows are fine (although possibly keep them a bit more higher up) etc. Video angle: try filming from a 30 degree angle from behind or so. Another angle to see any knee caving/foot position is good too.
Deadlift:
I really can't find anything bad here, except back position deteriorates somewhat after first rep, but it's not bad. Just focus on resetting each rep.
Person B
Squats:
Is this a person with bad flexibility? Looks like he's in physical pain going down.
- Wobbly knees, depth is too shallow I think but hard to say
- Keep elbows up to keep weight on shoulders
- Looks like he sits a bit back on the way up, causing a slightly irregular bar path
Not as good as person A obviously. I'm not familiar with the box squat though.
Deadlifts:
Very good, only bad thing I could see is eyes straight ahead which might get your neck into trouble.
All in all pretty good lifts I must say.