That's exactly the question: was the t-shirt was inspired by the artist in question, or not. And I'm starting to come around.

The dress of T-shirt Alice bears more resemblance to the artist's original than it does to the Disney version: http://25.media.tumblr.com/tumblr_lnarc6bdBm1qfkdyso1_500.gi...

The arm/hand position seems nearly identical as well. http://25.media.tumblr.com/0266dadc485f9ffa5a1fee696fd8a32c/...

Before you say "that could be a coincidence" - of course it could. The question at hand is "is it coincidence, or did Disney copy the artist's work?"