Lego Land.

[keannu]

Jim worked on his new home before wedding, and on the first day of marriage, they come to see the home and talk like this. Is "Lego Land" a messy place? It's translated as a mess, it seems like an amusement park to be used as a metaphor for a messy place.

g.w
Mel- I love it, you must have worked like a month of nights.
Jim- Yeah, don't be too impressed.The inside still looks like Lego Land.
Mel- I don't care. It's our home.

[Michael84]

not a teacher

I don't think an amusement park can be used as a metaphor for a messy place. Legoland parks are mainly designed for kids.
I don't know when this episode was filmed, but it may refer to the fact that Legoland California which opened in 1999 wasn't finished yet at that time.

[Ouisch]

I think Jim was using "Lego Land" as a metaphor....the house wasn't completely finished and some of the furnishings were hasty odds and ends he'd put together. "Legos" are building blocks that were originally meant as a children's toy, but today a lot of adults enjoy building large projects (like furniture) out of them.