Can you determine Protoss Buildings while still under construction?

If an opponent protoss warps a building, all buildings look the same, or is there a hint, what kind of building it will be once it is finished?

Solution 1:

You can click on it if you Enable Enemy Unit Selection in the Options and the name will be visible. In addition, the outline of the building is faintly visible later on in the warp, and you can make an educated guess based on the time what it is.

Solution 2:

They are all different, either differing in size or shadow. Someone posted a good guide to this on /r/starcraft years ago:

Stargate (has shadow), Twilight Council/Gateway, Robotics Facility/Forge. I would recommend you just play a game against a Protoss friend, get him to make a lot of money and build every building in a line, scout them before they finish, take a screenshot and compare.

Obviously this only when you don't get time to click on the building when you scout, if you only get a glimpse and you need to know if it's a gate or a robo, or a pylon or a dark shrine (that distinction is more obvious).