Why does the current enter the negative terminal of this element and it is still absorbing power?
Resistors aren't polarised. The positive and negative are simply labels, and someone has written the v2 labels the wrong way up.
Alternatively, this is a homework question asking for a negative value for v2. If you put the negative lead of a voltmeter to the -v2 and the positive lead to +v2, you will read a negative vale on the voltmeter. If you swap the leads you read a positive value.