The name means just "lobster in/on a roll" - with roll meaning " a small bread" rather than the act of rolling something. This does look delicious, but it is also somewhat atypical of the dish as I know it. The bread looks underdone and untoasted and the lobster is just sort of sitting on top, weirdly. Typically, the lobster is loaded into a slice in the roll and there is much more of it. Paradoxically, you can eat a proper lobster roll without a knife and fork, but this one seems to demand that you use utensils.
A google image search will demonstrate more clearly, but I could describe it as "an unholy amount of lobster salad in a hotdog bun."
Also - worth noting: you can make a lobster roll with the shellfish dressed with either butter or mayonnaise/lemon. Differences are regional and although it causes mostly good natured fights, I think both are nice. This one appears to be of the butter variety.
[I ate] a lobster roll in Boston (i.imgur.com)