Is this Pokémon Emerald cartridge fake?
This appears to be a legitimate card with a newer (SRAM) chip.
Other sites identify similar Pokemon Ruby chip as legitimate
And another identifies a similar chip as well (Note in the following image, only the upper card is legitimate, but has the same smaller chip style on the right)
The board is designed to take two different form factors for the component.
If you look at the PCM, you will see a smaller white box which matches where the chip is, and the parallel tracks are on the board, under the white marking.
If you look at the marking for the box you will see it is for 1M/512K flash. I don't know if the form factors are related to the size of the flash, or the providers.
Aa to the difference in gameplay between this and Ruby and Saphire, the pokemon have an animation at the start of the battle, and you capture a green dragon instead of a red or blue one.