not a gamebreaking issue, or anything major. Gilnean fans already know what Gilneas flag looks like
but the flag that we see in Gilneas City does not in anyway look like the Gilnean flag,it shows a triple-scar (probably a symbol of wolf.) and a circle.
it is explained that this is the Gilneas flag after the second war. putting that aside, if anyone is familiar with photoshop or image editing they'll likely notice that the symbol has a "blending" effect. (to put it simple : it has a glow) and a glow is not something I've seen on old flags (at least not the way they're shown on the Gilnean flag) this might look like a nit pick but it appears that this flag was supposed to be featured for the "battle of Gilneas City" but when the purpose of the city changed they didn't bother to create a new flag. and decided to use it for the current game.