A very clever person at Sheffield History has identified this view as Kelham Island - https://www.sheffieldhistory.co.uk/forums/topic/17004-old-postcards-of-the-don-valley-but-actual-places/?do=findComment&comment=142763

Hugh

Hi Hugh,
Would this be what later became the Union Grinding Wheel?
If so, my great grandfather had grinding wheels there with several men working for him, his own sons included.

Regards,
Marlene C.

If that thread is correct in saying that the postcard was issued c1905 then the Union Wheel already existed and was beyond the buildings on the right and round a slight bend in the river. The far end of the Union Wheel was right up against the bottom of Corporation Street.

Hugh