Upload & Sell: On
I think the image has an interesting mood, partially created by the light and partially by the characteristics of the film.
In terms of weaknesses, here is my take:
I don't think the problem is so much lack of detail in the shadows. I think it is more of a problem of lack of detail in general for the interesting parts of the image and the inclusion of detail for not very interesting parts of the image. For example, in the original there are two elements that are rendered with detail and decent exposure: the roped-off end of the carpet and the heating unit on the right wall.
RustyBug's crop does a good job at eliminating those distractions and provides a very nice composition but it also emphasizes some of the weaknesses in terms of lack of detail. We can't see the expression of the man and he is standing in a very neutral way so there is not much story there. He serves mainly as a device to lead us to the main altar. Unfortunately the detail in the altar is blown to white and is out of focus. The windows around the altar also lack enough detail to appreciate.
If the man was kneeling in prayer and/or it had been possible to capture the side of his face, it might have been possible to make the man more of the focal point and the subject of the image. As is, however, this looks more like a "tourist" shot where due to a shortage of time, possibly not having the right equipment (tripod), and not wanting to disturb the people in the church you take a quick photo from the back. I have many of these shots from churches in Mexico.