JSFiddle - React, Tailwind, and code Playground

HTML

<div class="block-1">
  <p>Текст текст текст</p>
</div>
<div class="block-2">
  <p>Текст текст текст</p>
  <p>Текст текст текст</p>
  <p>Текст текст текст</p>
</div>

CSS

.block-1 {
  width: 200px;
  height: 50px;
  border: 3px solid black;
  float: left;
  text-align: center;
  background-color: white;
  position: relative;
}

.block-2 {
  width: 140px;
  height: 200px;
  border: 3px solid black;
  float: left;
  text-align: center;
  padding-top: 40px;
   background-color: white;
}

.block-1::after {
  content:'';
  display: block;
  position: absolute;
  height: 50px;
  width: 6px;
  background-color: white;
  top: 0;
  right: -6px;
}