I wasn't sure about the relevance of the dogs in relation to the passage of time which is the central tenant of this sonnet (maybe because dog years are shorter?), however in reading around the sonnet I did realize the rather pleasing use of the wheelchair here. It seems that this being #60 is deliberate as it refers to the number of minutes in an hour (and refers to minutes too) and the wheels are used to represent the clock ticking forward. This metaphor is perhaps a bit overly done since the short film has too many shorts of the wheel crushing plants, or going through dead leaves, and such things, but it does help the text and make it more accessible.
The 'home movie' shots of dogs running in the park doesn't totally work or add much, but mostly it does connect to the text and make it more accessible as an idea. Still a bit heavily done, and still not sure about the dogs but it is another solid but yet slightly unremarkable film in the mostly reliable series.