As explained in What's the Truth About... Glatt Kosher the term glatt does only mean that the lungs are smooth and would not have to be checked further to make sure that the animal is kosher.
BTW a giraffe is kosher as it is a myth that there is a problem because of the long neck. Actually, the long neck makes it easier to slaughter.
The term has come to mean "definitely kosher" and people tend to use it as an advertising ploy or to assert that they follow various chumros even though the exact meaning does not apply. It is also used even in a situation in which there are no chumros that could be applied just to try to get people to feel the "my product is kosher beyond a doubt".
Misconceptions about the meaning of glatt are so widespread that, for
many, the term glatt has colloquially taken on the implication of a
higher standard, similar to the term mehadrin. In addition, some
caterers or stores may have only one kashrut sticker that they use on
all products, and hence the sticker on the corned beef sandwich and on
the omelette will both say "glatt kosher." Although it is technically
inaccurate to label chicken, fish, lamb, or dairy products as glatt,
it is not uncommon to find such labeling. In the majority of cases, it
is probably not being done to mislead; but in some instances it may be
intended to imply that the product was processed under a superior
hashgachah, as per the term's informal usage.
Note that "lamb" is mentioned above because the adhesions that can be peeled from the lungs leaving the animal kosher only applies to large animals like cattle. Lamb is not subject to the leniency so it is not "glatt" or "non-glatt"
Tzarich Iyun: Glatt Kosher
An important postscript is that the Ramah’s ruling is defined as
non-applicable to young, tender animals such as lamb, kid and calf
(Ramah, YD 39:13). Therefore, all lamb chops, veal or other meat from
young animals must be glatt Beit Yosef, even for Ashkenazim.
Is the use of the term "Glatt Kosher" a case of "Genivat Da'at"? points out that
In this context, it is more of a "term of art" or a common borrowed
expression rather than purely a marketing tool.