You'll know it's lavender once the true leaves come out, because you can smell it.

Years ago I managed to sprout lavender seeds, and only one of them stayed strong. It's still living in a pot, and now it's practically unkillable. When the stems become woody, they can benefit from heavy pruning too.

Nice germination results. Did you do any pre-soaking of the seeds? Looks like you just scattered them over the surface, put them in the high humidity greenhouse, and let 'em do their thing.