Can it?---of course it can.
Will it?---depends on a number of variables.
Can it?---of course it can.
Will it?---depends on a number of variables.
Depends on the object and the window.
That paperweight Hippy mentioned, wouldn't even cause a slight crack in a window meant for the upper levels of a high-rise building - because they are designed differently than the windows of a normal house.
I like my horse just the way he is ! I wouldn't want it any other way!
Here's a couple of thoughts.
If the head was bigger it would be heavier and require stronger neck muscles to keep it usable, this would probably unbalance the horse, which is an eating/running machine.
A bigger head would also (probably) be less streamlined, and horses like to run.