This video says about itself:
Glaucous Gulls are regular visitors to West Cornwall, but adults are few and far between. This one is a very confident individual, hanging around the harbour waiting for free hand-outs from the local fishermen. It’s an easy life for some!!!
From the Go-South blog:
19 February 2015 – Rare Gulls at Essaouira
Two rare gulls at Oued Ksob seen by Dominic Mitchell: a second-calendar-year Great Black-backed Gull (Larus marinus) on 14 February and a third-calendar-year Glaucous Gull (Larus hyperboreus) the next day [probably the same bird seen in December and January in Essaouira harbour]. … photos appear in Dominic’s blog at www.birdingetc.com.
Great black-backed gulls are not that rare in western Europe, eg the Netherlands. However, they are in Morocco. While glaucous gulls are common in Arctic Svalbard, but not in western Europe, and certainly not in Morocco.