If you want to align it, you can use flexbox, as recommended above and to separate the boxes using margin or padding and you have several methods so that the image is not distorted.
I leave you 3 examples, check all, but above all the last one that is what I think you want:
Objet-fit: COVER
.caja {
width: 100%;
text-align: center;
display: flex;
flex-wrap: wrap;
align-items: flex-start;
margin-bottom: 1em;
}
.foto, .video{
display:inline-flex;
vertical-align: top;
}
.foto{
width: 30%;
}
.video {
width: 70%;
}
.foto img {
width: 100%;
height: auto;
max-height: 393px;
object-fit: cover;
}
<div class="caja">
<div class="foto">
<img src="http://picsum.photos/900/450">
</div>
<div class="video">
<iframe width="700" height="393" src="https://www.youtube.com/embed/TxAUdSYo1Y4" src="#" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen=""></iframe>
</div>
</div>
<div class="caja">
<div class="foto">
<img src="http://picsum.photos/901/451">
</div>
<div class="video">
<iframe width="700" height="393" src="https://www.youtube.com/embed/wl3_hAFs1gM?rel=0" src="#" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen=""></iframe>
</div>
</div>
<div class="caja">
<div class="foto">
<img src="http://picsum.photos/902/452">
</div>
<div class="video">
<iframe width="700" height="393" src="https://www.youtube.com/embed/SR1YY-olieU?rel=0" src="#" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>
</div>
</div>
Object-fit: contain
.caja {
width: 100%;
text-align: center;
display: flex;
flex-wrap: wrap;
align-items: flex-start;
padding-bottom: 1em;
}
.foto, .video{
display:inline-flex;
vertical-align: top;
}
.foto{
width: 30%;
}
.video {
width: 70%;
}
.foto img {
width: 100%;
height: auto;
max-height: 393px;
object-fit: contain;
}
<div class="caja">
<div class="foto">
<img src="http://picsum.photos/900/450">
</div>
<div class="video">
<iframe width="700" height="393" src="https://www.youtube.com/embed/TxAUdSYo1Y4" src="#" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen=""></iframe>
</div>
</div>
<div class="caja">
<div class="foto">
<img src="http://picsum.photos/901/451">
</div>
<div class="video">
<iframe width="700" height="393" src="https://www.youtube.com/embed/wl3_hAFs1gM?rel=0" src="#" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen=""></iframe>
</div>
</div>
<div class="caja">
<div class="foto">
<img src="http://picsum.photos/902/452">
</div>
<div class="video">
<iframe width="700" height="393" src="https://www.youtube.com/embed/SR1YY-olieU?rel=0" src="#" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>
</div>
</div>
Make it responsive
Depends on the result you want to get, now for the responsive, I do not know if the best way is to keep the image on the mobile side because as you see or cut or shrinks too much, it is best to use a half querie that in Desktop behaves as you need and on mobile the image occupies the entire width or only half.
.caja {
width: 100%;
margin: auto;
text-align: center;
display: flex;
flex-wrap: wrap;
align-items: flex-start;
justify-content: center;
padding-bottom: 1em;
}
.foto, .video{
display:inline-flex;
vertical-align: top;
width: 100%;
max-width: 700px;
}
.foto img {
width: 100%;
height: auto;
max-height: 393px;
object-fit: cover;
}
@media (min-width: 960px){
.foto{
width: 30%;
max-width: initial;
}
.video {
width: 70%;
}
}
<div class="caja">
<div class="foto">
<img src="http://picsum.photos/900/450">
</div>
<div class="video">
<iframe width="700" height="393" src="https://www.youtube.com/embed/TxAUdSYo1Y4" src="#" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen=""></iframe>
</div>
</div>
<div class="caja">
<div class="foto">
<img src="http://picsum.photos/901/451">
</div>
<div class="video">
<iframe width="700" height="393" src="https://www.youtube.com/embed/wl3_hAFs1gM?rel=0" src="#" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen=""></iframe>
</div>
</div>
<div class="caja">
<div class="foto">
<img src="http://picsum.photos/902/452">
</div>
<div class="video">
<iframe width="700" height="393" src="https://www.youtube.com/embed/SR1YY-olieU?rel=0" src="#" frameborder="0" allow="autoplay; encrypted-media" allowfullscreen></iframe>
</div>
</div>
I do not know if it's the same responsive effect you want, put your comment to verify what would be the best option.