I'm a bit confused about what really is being interpreted here, because my reading of the specification indicates that the entire image is read as a single expr

I'm a bit confused about what really is being interpreted here, because my reading of the specification indicates that the entire image is read as a single expression in the lambda calculus but the graphic interpreter looks like a procedural execution at the first glance. Is it just a visualization of beta-reduction in progress? EDIT: I think I got it and I think calling this as an "encoding" is a misnomer. The program starts with a single term `turnstyle(x, y, dir)` which gets lazily evaluated to the actual term. So not only the evaluation might be lazy, but the parsing is also lazy and this is a key point of this esolang which should be highlighted more in my opinion.