I don’t see an issue with it. Many factors influence how “useful” a picture is, and even then its usefulness is based on one’s subjective perception rather than a global measurement.
For someone who is mapping fire hydrants on OSM 1-3 pictures of a single fire hydrant can be more helpful than 300 images of the street, as opposed to someone who’s mapping the lanes of the street where a long sequence is more helpful.
I’ve taken pictures of single objects before too, like a sign or important landmark. For example: https://www.mapillary.com/map/im/5FBafCoJTnkQ7rEl4Cbqzw
Well even if you only capture 1% of the way you’re going it can still be helpful if the pictures have been taken at the right position - and if they are in the right position is often just coincidence so better take a few pictures than none at all, especially on ways that haven’t been captured yet.