yeah, personally i wouldnt go for that ‘designed as a frame grab’ thing. movies tell a story in a sequential series of frames. the whole concept/story/theme isnt explained all in one shot.
still images have to express their intentions within that single picture (or as part of a series, but still every image has its conceptual voice). the fact that they dont move means that much more time will be spent by the viewer in studying the image, meaning that it would require more information and detail to have any sort of meaning.
look at graphic novels and how they carry their message across. each frame is physically static, sure, but each frame also has its influence on the whole piece.
context through scene development (background, other characters, clearer definition of the actual subject) or through supporting images (a triptych, maybe? a longer series of panels?) would definitely improve the image’s readability.