Hi,
The gap is because the background image mode is set to contain the image, not to cover the space. The isotopic layout, which you are currently using is a fixed width/height ratio results laytou, and is probably not the best for containing images – as the white space needs to go somewhere as the ratio is fixed.
You could perhaps try a theme with the “horizontal” layout, which you can then set to not use scrolling, so the items will be printed one after another.
It is the deafult behavior for the results container to close the results, whenever the search elements lose focus, you can change that here: https://i.imgur.com/OoTMx30.png
