Problem after Back Geocoding

Hey there

I am trying to learn SNAP at the moment by following this https://www.youtube.com/watch?v=VE38mGI8h-I video. I downloaded the same to data files, did the split and added an orbit-file, but after geocoding my slave image is missing. When using the SRTM 1sec I produced the slave image, but it did not look like the one in the video, where all the background was removed and only the island remained.
Can anyone help me with this? I just want it to look like that in the video.

Thanks

Please follow the steps carefully , and write down all and implement step by step, might be one step is missed, for instance Enhanced Spectral Diversity, ESD.