Space, they say, does not have the boundaries; it's three-dimensional, and the very thing that makes it possible for objects and events to exist. Can that thing we see in the mirror be considered space?
If space is boundless, then it must be. But is the space within the mirror three-dimensional? Is it possible for objects and events to exist - to take place - within it?
Then, there is of course the question of the photograph itself. Is it space? If we stick to the physicist's definition of linear space, it can't be. It has boundaries, the frames. And it's only two-dimensional. However, the photographic "space" does make objects and events exist or can be created to exist.
Let's also consider space's fourth dimension that forms a continuum with time and hence is called spacetime. Now you have the very thing - contentious as it might be - that defines our perception of the universe.
Welcome to space within space.