How to make one Image load first on a webpage before the other 20 Images

Hi,
In my webpage I have 20 .jpg Images. Sometimes it can take about 10 seconds before the webpage is loaded and all images are seen.
I have one .jpg image that are more important to visually see first before the others.
 
So my question is if it is possible to "force" one image to load the Very first to be seen visually? I dont know if this works in a specific order or the webpage renders it by random?
Thank you
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