This second-cycle gull was photographed in Galveston County, Texas, on January 26, 2006: while it is probably an unusual LBBG, it does have some structural characteristics and plumage features associated with YLGUs of this age (and the mantle shade - about similar to Laughing Gull - is within range for Azorean YLGUs):
Note how short the wings are, compared to that expected for LBBG; also note the extensive pale areas in the "2nd-generation-like" 3rd-generation scapulars and wing coverts, and the single rather pale gray tertial plus the sub-tertial above it:
Below with Am. HERG to left; LBBGs in front and behind:
Note that this bird has retained dark "shins" into its third calendar-year - something that is supposedly strongly associated with Atlantic YLGUs:
