The image is an image of a dog sitting in a burning room with a cup of coffee on the table in front of him. The flames surround him and there is a cloud of smoke above him. The image is drawn cartoon style. The dog says “This is fine” while sitting there calmly wearing a silly hat.
The image is like a text because it tells a story. You can guess the dog’s thoughts just by looking at the image, without a description of what they are feeling. This meme also reads similarly to a text because it is designed to be read from the leftmost image to the rightmost, just like the words in a sentence or the pages in a book.
There is irony in the way the dog is reacting to the burning room because you would expect him to be in a panic but he is doing the opposite: sitting there calmly.
This meme is typically used to describe a person who is surrounded by chaos and disaster and feels so overwhelmed that they resign to their circumstances and choose to calmly accept what is coming their way.
There is not really anything you need to know to understand the meme; the meme speaks for itself. It may help to relate to the dog but it is not necessary to do so in order to understand the intention.