This can be seen as a homage to Wilhelm III. to be interpreted by Orange. The picture could have been made in the early days of the Franco-Dutch War, which lasted from 1672 to 1678, at a time of internal turmoil in the Netherlands, when hopes rested on the Orange. In addition, a positive attitude towards the Holy Roman Empire of the German Nation is evident, for example through the chandelier with the Habsburg double-headed eagle. The picture is therefore not a praise for painting, but rather a statement by Vermeer’s on the current political situation in the Netherlands.  
There are no drawings that can be clearly attributed to Jan Vermeer. Their absence has led many authors to assume that Vermeer did not need study drawings for his work. This contrasts with the controversial drawing Maid with Foot Warmer, which proponents ascribe to Vermeer and dated to 1655. It is 25.5 cm × 16.5 cm in size, made with chalk on blue paper and is now in the graphic collection in the Weimar Castle Museum. Proponents attribute the assignment of the drawing to Vermeer mainly to stylistic similarities and the similarity of the monogram on the foot warmer with the signatures on the paintings Letter Reader at the Open Window and View of Delft. For example, doubters cite the blue drawing paper as a justification for their position, since they assume that this paper was only produced in later centuries. This is contradicted by a representation by Karel van Mander, who lived before Vermeer and was the author of the Schilderbook. Van Mander led a pupil of the portraitist Michiel Miereveld from Delft: “He is eager to examine the most mature beauty of the art of painting, practices various self-invented manners in coloring, also draws on blue paper in between …” That means that it was long before Jan Vermeer Delft area gave blue drawing paper. 
The choice of paints used was an important aspect of Vermeer’s elaborate painting technique. He is best known for his generous use of the expensive natural ultramarine (“Maid with a Milk Jug” and “Letter Reader in Blue”). The pigments lead tin yellow (“letter writer in yellow”), madder (“Christ with Mary and Martha”) and cinnabar were also characteristic of him. For his cityscapes and backgrounds, Vermeer also used earth colors, bone black and the cheaper blue pigment azurite.  
Jan Vermeer was a pioneer of new design principles in painting of his time. He used a balanced division of the surfaces, with which he also represented complex facts and structures simply and with a few elements. The geometry played an important role in the composition. Vermeer dealt with the light in his pictures in such a way that almost the impression of open-air painting was achieved. Furthermore, he did not use gray tones to represent shadows.
The Dutch painter Vincent van Gogh writes to the French painter Émile Bernard:
“It’s true that in the few paintings he has painted you can find the whole gamut; but the lemon yellow, the pale blue and light gray is as characteristic for him as for Velázquez the harmonization of black, white, gray and pink. “
It is repeatedly claimed that Jan Vermeer used a camera obscura when painting his pictures.  Norbert Schneider, for example, writes: 
“We now know that Vermeer made use of the camera obscura in most of his pictures, in a way that does not hide the conditions of this medium, but actually makes it visible, such as the edge blurring and points of light, the famous ‘pointillé’ ‘can be seen. In this way, the pictures acquire an ‘abstract’ quality because they do not pretend to reproduce reality as it is, but as one sees it, […] One can say that the ‘camera obscura is closed a source of style. “
Not all experts share this opinion. The topic has been examined in a large number of studies. However, even among those scholars who are certain that Vermeer did indeed use a camera obscura, there are still great debates about the extent to which he did so.  The discussions began when the American lithographer Joseph Pennell first pointed out the photographic perspectives in the Vermeer painting The Soldier and the Laughing Girl in 1891.