Just type the URL of the image file into a cell, like
file:///path/to/your/photo.jpg
If on Windows include the drive letter, I think it then would be like
file:///C:|path/to/your/photo.jpg
or
file:///C:/path/to/your/photo.jpg
(not sure, not using Windows myself).
Or if it’s in the web then the web URL, https://example.com/path/to/photo.jpg
To not having to replicate a fixed file:///path/to/your/
each time and be more flexible you could also enter that as string into one cell, for example in A1, and then use the HYPERLINK() function to create a link:
=HYPERLINK(A1&"photo.jpg";"cell text to display")
Or create a file listing as text on the command line and edit that as needed and import it or copy&paste it.