Pretty sure she is on a petrol one - there is a fuel tank above the front wheel, and you can see the fuel line going into the throttle body above the single piston engine. You can also see the exhaust and muffler below and behind the piston.

Also looking into it more, I don’t think the Autoped was ever offered with an electric motor. Apparently the confusion comes from the fact that the company was bought out by the battery manufacturer Eveready, and sold as Eveready Autoped. Eveready modified the Autoped by adding a battery and ignition coil, replacing the original magneto system, but propulsion was always by means of a petrol engine.

I don’t think the one in the photo has the battery and coil however - the coil can be seen here in front of the gas tank, but is missing in the OP photo.

Edit: looks like the batteries and coil might have been separate - here is an article from 1917 that describes the Autoped as having a magneto ignition system (no coil) and also a battery box to operate the front and rear lights. And here is an example with an ignition coil powered from the wheel, but no battery box and no lights (which were probably optional) The one in the OP does appear to have the battery box and lights, but uses the magneto ignition, so it’s the same model as described in the article.

Fast film (you can see how grainy it is when you zoom in a little) and shooting in full bright sun = you can shoot very short exposure and freeze motion. There were already cameras in the 1930s with mechanical shutters that could do 1/500th and even 1/1000th of a second exposure, which is plenty fast for this type of shot.

The lens looks pretty fast too - depth of field is very shallow, although part of that is also due to possible use of medium or large format - faster lens (lower f stop) and larger film both allow more light capture, and therefore faster exposure as well, but at the cost of less depth of field.

Edit: here is a good print of the full frame - looks like ~1.50 ratio, so probably 35mm film (not medium or large format) - I can’t find a lot of information about what cameras Max Alpert used in the 30s, although he did use a 35mm Leica on at least some photos from that era. A Leica III could do 1/1000 in 1935 for example. The early Soviet cameras from the 1930s were also basically direct copies of Leicas. The frame also looks a bit underexposed, which could be due to pushing the exposure for more speed.

I think those might actually be frosted glass cups.

Here is the best copy I could find, and the flared edges do not look like plastic cups - also the shiny inside and matte outside looks more like glass frosted on the outside.

PP was not in commercial use until 1957 (not sure when it was first used for cups), PET disposable cups weren’t a thing until the 70s. Disposable cups in the 50s would have been wax paper.

Once you finish it, it’s actually really fun watching other people’s playthroughs as well - getting to relive some of the moments vicariously through other people’s eyes is almost as much fun as experiencing them yourself the first time.

It’s also quite amazing just how different each playthrough can be, since the game is so non-linear, people take some crazy paths to get to the end ! It can be frustrating as well when someone just can’t see what is in front of their face though :)

There are also so many subtle elements scattered around that most people miss on their first playthrough, and watching someone else play it really made me appreciate many of the details I missed on my own playthrough and even make connections I didn’t before, and understand aspects of the story that I didn’t fully get the first time.