that's interesting. It has been mentioned on Zoochat before by Mr. Wukong that tree kangaroos and echidnas should not be mixed: Australian mammals in overseas zoos
Tree kangaroos are not just prone to stepping on loose quills lying around and thus hurting their feet; due to a strange habit nature has bestowed upon them, they have the habit to eat echidna quills, even whole quills. Nobody knows why, but it doesn't do their intestines any good...
It looks like the echidna in this photo has had the ends of its quills removed somehow. Its not unusual for some quills to be blunt but these are very uniformly shortened. Could the tree kangaroo (or tree kangaroos if there are more than one in the exhibit) be eating them directly off the echidna?
