Yes, those look like wooden propellers. And in the first photo they’re leaning against what looks like a tail assembly attached to a pipe.
There’s not a lot of scaling information in those photos, but what there is tells me these aren’t “toy” sized drones, they’re actually edging up to small ultralights.
Unless you’re using jet engines (and they’re not) this isn’t rocket science. The information needed to build a small, even a really small, aircraft is out there. Remote control technology has become better, cheaper, and easier to use. Bomb-making tech has been out there forever.
The “big” obstacle is combining all of the above in a workable package. But if you’ve got money and don’t have to worry about making something a human could ride on safely people with mechanical skills to, say, work on a car could figure out how to make it all work pretty quickly. There is skill required to use it all, but there are software “games” as well as frank training programs for remote control aircraft out there that allow a person to practice without breaking actual objects.
There are plenty of companies around the world that make and sell parts to use for tiny aircraft that weigh ounces up to full size, people-carrying aircraft. Or they could be cannibalizing small aircraft. Or both.
That said, getting a suicide bomber to drive a car into a crowd of people IS easier and probably cheaper to do, which is probably why we see car bombs and suicide bombers more often.
Sure, governments do keep an eye on people with the needed skills (pilots, aircraft mechanics, commercial drone operators) as well as folks who sell certain items (like propellers) but the truth is that some dedicated nutjob can put all together in a garage without the neighbors being the wiser. Given that, I’d be more shocked if something like ISIS didn’t have workshops for this in territory they control than the fact they do have them