I am trying to figure out why photos inside a folder don't move up when a photo above it in the folder has been deleted.

I am trying to figure out why photos inside a folder don't move up when a photo above it in the folder has been deleted.

Here is my scenario.

I create a new folder and call it "pictures of trip". I put 200 photos from the trip. Days later I go back in to the folder and decide I want to delete some of the photos. I randomly delete photos inside the folder. When I delete those photos, the ones left in the folder, don't "move up" and fill the "space left or vacated" by the deleted photos. I ONLY want to look at the photos as ICONS. In the past the photos would shift upwards and fill in the voided space. Now I have huge gaps between photos. I don't want to spend the large amount of time manually moving each photo "upwards". I am a photographer and sometimes have hundreds too thousands of photos in a single folder.

Please help me to get them to close up the gaps.

Thank you in advance,

Strnge