What does 'subject' and 'object' mean respectively?

Early photography continued the trend toward the
imprisonment of the subject and the object of representation.
During photography’s first decades, exposure times were
quite long. For instance, the daguerreotype process required
exposures of four to seven minutes in the sun and from
twelve to sixty minutes indoors. Early photographs
represented the world as stable, eternal, and unshakable.
And when photography ventured to represent living
things, they had to be immobilized. Thus, portrait
studios universally employed various holding devices to
assure the steadiness of the sitter throughout the lengthy
time of exposure. The devices firmly held the person in
place. In other words, a person who wanted to see his own
image became a voluntary prisoner of the machine.
vsureshI think they refer to the photograph device and the thing to be photographed.
I didn't answer because I found the use of the two words puzzling, but the subject in photography is the thing being photographed. I still don't know what the writer means by "object".

Previously the author has explained a "subject" as being "author, reader, spectator or voyeur" and, for example, talking about a camera obscura, has said:

"we see the subject enjoying the image inside a tiny room, oblivious to the fact that he had to imprison himself inside this 'dark chamber' in order to see the image on the screen"

So, it seems that "subject" is the person looking at the photograph and "object" (or "object of representation") is the person whose photograph is being taken. SInce the latter is normally called the "subject", it's pretty confusing.

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I think they refer to the photograph device and the thing to be photographed.
 enoon's reply was promoted to an answer.
Hi enoon, thank you for your answer.
Imprisonment of both makes me think that both the device and the person to be photographed need to be stay put in a position.
Please share your views.
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 GPY's reply was promoted to an answer.