The way how to use "by" in the quoted sentence

I saw a paper with "Dimitar Berbatov has shown it is not just the crowds he is drawing this season by revealing a touch of artistic flair.The mercurial Bulgarian is clearly as effortlessly talented with a pencil as he is with his feet BY as he has produced a series of stunning caricatures." written

In the 2nd sentence, the writer said 3 things
a./ The mercurial Bulgarian is clearly effortlessly talented with a pencil
b./ The mercurial Bulgarian is clearly effortlessly talented with his feet
c./ he has produced a series of stunning caricatures

but I couldnt figure out any reasons "by" was used right after the sentence B "The mercurial Bulgarian is clearly effortlessly talented with his feet"

Would appreciate if anyone could tell me the reason. Thanks in advance.