Region displays with corners cut off

Questions
1

Does anyone understand this? The region is correctly defined as the first unit square, but it is displayed with the corners cut off:

Block[{reg}, Column[{
   reg = Region[ImplicitRegion[0 <= x <= 1 && 0 <= y <= 1, {x, y}]], 
   Element[{1, 1}, reg]
   }]]

7691b1.png
7691b1.png848×267 1.79 KB

If you draw the region with RegionPlot, everything is fine:

RegionPlot[0 <= x <= 1 && 0 <= y <= 1, {x, 0, 1}, {y, 0, 1}, 
 ImageSize -> Small]

4285b2.png
4285b2.png241×238 1.16 KB

2

It seems that Region makes a rough plot to display quickly.

3

I don’t think so. Actively cutting the corners would be even more complicated than showing the region as is.