Incredibly different.

I highly doubt a normal engineer is going to be giving a demo to their team with high stakes in the first three or so months. I understand if they're possibly a senior engineer, architect, or lead of some sort because they were probably hired with a plan to spearhead a specific project.

I'd say in the average case a new engineer will have enough time to at least break the ice with their new team before being put into a high pressure situation.

I gave a demo of my intro project after a month to my 100 person org at my last company and I was a new grad. In fact, when I was an intern, all interns did project demos at the end of their internship.

Was a hundred K on the line? Clock ticking? Random subject you couldn't have/hadn't prepared for? :D

Was the presentation of that demo standing between you and being fired or keeping the job?