<div class="ava">
    <img src="https://images.unsplash.com/photo-1488190211105-8b0e65b80b4e?w=500&amp;h=500&amp;fit=crop" width="200px">
</div>

<div id="profiles_show">
    <div class="block">
        <div class="subheadline"></div>
        <div> <p> Lorem, ipsum dolor sit amet consectetur adipisicing elit. Ex eligendi qui voluptate tempora iure dolores architecto commodi ducimus minus alias fugiat necessitatibus quidem aliquid, explicabo sapiente delectus in. Aliquid, nesciunt?</p></div>
    </div>
</div>

body {
  width: 1000px;
}

.ava {
  width: 50px;
  height: 50px;
}

.block {
  width: 500px;
  height: auto;
  margin: 0 auto;
  position: relative;
}

#profiles_show .block {
  display: none;
}

.ava:hover ~ #profiles_show .block {
  display: block;
}