To be honest this is far less interesting than the things elephants do in the wild.
Aside from the usual stuff humans like about some animals, like pair bonding, raising their young and living as a family, and being very social with each other and even other species (including humans), there are a lot of other human-like traits of elephants. Elephants have astonishingly long memories (it's a wives tale that turns out to be true). They'll pause on the spot where loved ones have died, even many years later, and groups will console each other after a loss--having a funeral of sorts. They remember humans who have been cruel or kind to them in the past, and behave accordingly. They communicate vocally and are known to express a range of concepts this way--not just warnings, but also greetings, calls, and "names" (unique identifiers specific to each elephant). And, recently humans "asked" elephants to carry cameras into the forest for them, to help study tigers. Since elephants and tigers are on peaceful terms (what's a tiger gonna do to an animal that could crush it with one foot?) it worked well, and some amazing footage resulted.
Given all of this, it shouldn't be at all surprising that an elephant could be trained to paint a particular picture. It is rather unfortunate that it takes something like this to impress tourists of the intelligence of one of our closest intellectual peers, when elephants have so many more fascinating traits and ways of exhibiting impressive intelligence.