Taking the most probable and most objectively answerable interpretation ("Which has the closest scale?") the answer can be clearly decided:
According to the Star Wars Wiki the AT-AT is 22,5 meters high and 20 meters long. The 75288 set you purchased is 34 cm high and 38 cm long, this gives a 1:66,17 or 1:52,63 scale, depending on whether you take ...
LEGO boxes in Europe do not have piece count on the front. There is no legal requirement within EU to present this information on packaging.
Actually, depending on where you live, it may be odder to see boxes with part count on its front.
That set was produced from around 2009, and anecdotally, we've seen that the LEGO logo wasn't really added to the leg elements until around 2013.
There are also examples of legitimate accessories having no logo on them as well.