JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="col col--left">
        <div class="item">
            <img src="https://placehold.it/400x900" alt="">
        </div>
    </div>
    <div class="col col--right">
        <div class="item">
            <img src="https://placehold.it/500x400" alt="">
        </div>
        <div class="item">
            <img src="https://placehold.it/500x400" alt="">
        </div>
    </div>
</div>

CSS

img {
    width: 100%;
    height: 100%;
}

.container {
    display: flex;
    width: 700px;
    margin: 0 auto;
    border: 1px solid #000;
}

.col {
    flex-basis: 50%;
    margin: 7.5px;
}

.col--right {
    display: flex;
    flex-direction: column
}

.col--right .item {
    height: calc(50% - 7.5px);
}

.col--right .item + .item {
    margin-top: 15px;
}