There were more than 35,000 pictures of FDR taken. Two show him in a wheelchair. Why? Because the press almost unanimously agreed that — despite the huge news value — depicting FDR as a cripple would be bad for the war effort. The few dissenting photographers from that consensus were routinely blocked or deliberately jostled by the senior photographers so as to shield FDR from embarrassment and the public from its "right to know."
Okay, this is a subject I know virtually nothing about. I do, however, know that FDR became president in 1933 after winning the 1932 election. The war in Europe didn't begin until 1939, and the United States didn't enter the war until 1941. Under the circumstances, that "depicting FDR as a cripple would be bad for the war effort" can't be the primary reason nobody ever did it.