It will most definitely be a limited power of attorney for this event only. They should have called it "Representative Appointment Form" like other industries do.

The latter is technically a limited power of attorney too.

Edit: The following is from their EU POA form:

   This power of attorney shall become effective on the day of signature and shall expire if revoked by me/us in writing. This document shall be construed and interpreted as a general power of attorney and my/our Agent shall have full authority to act on my/our behalf in relation to my/our claims resulting from disruptions of flights pursuant to EU Regulation 261/04. I/we furthermore grant my/our Agent the authority to:

   *(1) undertake all appropriate legal – judicial and extrajudicial – measures appropriate to collect my/our claim(s) from the airline until the claim is fully settled;*

   *(2) collect and receive payments on my/our behalf.*