These are certainly more lively, serious attacks. The initial timing and spacing seems to be entirely unplanned.
The attacks are faster, yes. Serious? Since uke doesn't follow up with anything after each grab and over commits to each strike, I don't think so. And the timing and spacing are totally left up to uke since nage just stands there until uke has launched his attack despite the fact that uke plainly intends to do something more than just shake hands. Uke's body language and movement clearly foreshadow his intent.