It's hard to believe more structures weren't burned to the ground with the wiring from the "good ol' days." The National Electrical Code of the era barely consisted of 40 some-odd pages.

Are those power lines running into an open window off the power pole centre left of picture? Is that to code?

The upper level construction could have been due to planned obsolescence; git 'er built fast for the first summer season and if the owners made money, plow that into more permanent construction. Take a look at later pictures and you'll see this entrance radically changed at least twice over the years.

There was always pressure on the amusement parks to have new attractions every few seasons. The profits would likely go there first. Changing the overall look of the place would be in mind also. In the same vein, modern shopping malls go for makeovers every ten years or so just to be "new and exciting" to the customers.

The man standing with his wife at right appears to be checking his watch. One service window has been opened and looks about ready for business. Looks like flavored syrups for snow cones in those bottles.

Tarpaper roofing, siding, etc.
Walls made of balsa wood?
Talk about "temporary architecture."

Looks like the flag of Cuba on the left-most pole. It was a fairly new flag in 1905. Wish I could see the others!

Just an assumption, partly based on the electrical wiring that's connected to a board that's stuck under an open window, not that there's anything wrong with that.