JSFiddle - React, Tailwind, and code Playground

HTML

<div class="specific-image-container">

    <div class="specific-image-column">
        <div class='content'>flexible width column</div>
    </div>
    
    <div class="more-images-column">
        <div class='content'>fixed-width column</div>
    </div>
    
</div>

CSS

.specific-image-container {
    display: flex;
}
.specific-image-column {
    flex: 1;
    background-color: aqua;
}
.more-images-column {
    flex: 0 0 300px; /* new */
    background-color: red;
}
.content {
  height: 300px;
  display: flex;
  align-items: center;
  text-align: center;
  justify-content: center;
}
body { margin: 0; }