Interesting info about the radar mast censorship, not aware of that.
I would date this postcard as post war and not later than 1951.
As Scotchie says, there were a row of houses, and the Esplanade Hotel, in the cleared patch on the bottom left of the picture. These were demolished postwar, one imagines that they were heavily damaged.
This enabled the Wellington Crescent curve to be installed in the seafront railway line, thereby connecting the track on the Wellington Dock swing bridge directly to the line along the promenade to the Camber.
This eliminated the back-shunt onto the Prince of Wales pier which had previously been necessary.
The Wellington Crescent curve was installed in 1951. As the Esplanade Hotel and the row of houses had already been levelled in the above postcard view, I would venture to guess that they would have wasted no time in constructing the railway connection and that this view is in all probability taken in that year.