A beautiful presidential palace is of French architectural model, but constructed by a local specialist in 1980s. Very nice, but the entrance inside is restricted. So you may take photos only outside the fence.
You cannot enter the building, you can only have a glimps of it trough the main gate from the street. You take 1 selfie in front of it and move on to the temple complex next door. Nothing of interest to see at the palace itself.
You can't enter the palace or the grounds, the best you can do is see it from a distance at the gates and surrounding fence.
I'm sure you're bound to see it whilst visiting the nearby wats, you can't really miss the big white building, but don't waste your time detouring to it.
As all other contributors noted already, the palace can only be seen from the gate when passing by on the street. It certainly looks grand and surely is of importance, but shouldn't be listed as a tourist attraction.
You can't actually get in the Palace but its at the opposite end of the Laos "Champs Elysees" and near to Wat Sisaket so you can't really miss it. Worth a photo if you can get one that doesn't feature Asian tourists taking endless selfies!