We'll assume that you're using high quality research resources such as the BJP (British Journal of Photography).
When studying photography you need to become quickly aware that in most cases photography is produced as bodies of work as opposed to single images. Therefore when you're researching you should aim to identify the body of work rather than the single image. If your research is being conducted properly you'll probably be doing this anyway.
The books that we advise you to use in your research often do the opposite, they will present you with a single image which will then be analysed. It's down to you to identify the wider body of work and consider the work as a collective.
At the very least acknowledge the fact that your research is primarily examining one image from the wider body of work - use additional images from 'The body of work' and identify the name of the body of work/project or the time/place it was photographed in, as well as the period of time the images were taken during/over.
As an example...
This image here from http://www.artfund.org/assets/what-to-see/exhibitions/2014/Bailey's%20Stardust/BS1536P2.jpg
https://www.youtube.com/watch?v=_7S0zyYVgZM The actual story is very interesting and says a lot about the context of the time. Only through research, reading and watching videos are you going to start to get an idea of how this image came about. The same research then gives you an insight into different aspects of the way in which Bailey worked.
The image is a part of a bigger body of work, but the image on its own is interesting too.