It is an eau, in EDC concentration (Eau de Cologne). It is not supposed to last long and it doesn't last long. I think the range of products includes a huge "family bottle" format (400 ml) to be splashed liberally.
I don't know how big was your sample but I wish Hermès would release free 10 ml samples (for 2 applications).
Like with most citrus scents, any attempt to create a more concentrated version often results in a significantly different scent. Go for the Concentré
instead, it is very good.