An allen wrench (aka a hex driver) is pretty different from a "regular" screwdriver (aka flat screwdriver). The "L" shape we've come to associate with allen wrenches isn't what makes it an allen wrench.
(Interestingly (to me anyway), an allen wrench is often considered a driver (a hex driver or even an allen driver), not a wrench, because the tool inserts into the head of the object being driven, while a wrench goes around the head of the object. What's even more interesting (again, maybe it's just me!) is that this definition of wrench vs driver is not at all accepted in the tool community, and there's no clear consensus about what makes something a wrench vs a driver.)