I carry a picture of the graph of the equations in my head which I recall whenever I see an equation of reasonably simple form. For complicated equations I generate a mental graph of individual terms or even of factors within the terms. However, the reaction is conceptual, not in terms of a statement in English. Another form of visualization is providing interpretations for the symbols. I may even translate an equation mentally, just as I would with a difficult phrase in a article in French.
Experts always keep the physical meaning of equations in mind.
The equation itself is just a sequence of nonsense syllables. What is important is what the symbols mean. I have a mental image of my moving around a fixed starting point, changing velocity or not according to the situation. Sometimes I am the starting point and it is a car moving. Often I visualize a checkerboard pattern on the ground as a kind of graph paper.