I thought it was interesting to see the expression on Prince Fielder's face when he realized the camera was 'right there' ...
Now as to why it seems to be happening more often in front of the camers ... because (I think) it is happening more often and it is due to lousy impulse control on the part of the players involved. This is were I think MLB has changed so much over the past 10 years or so ... players have these temper tantrums in public, whether it be throwing a bucket of balls, firing a baseball into the stands, or shoving a teammate in the dugout, and they seem to go unpunished/undisciplined. Granted, we don't know all the goings on in the clubhouse and manager's office afterwards, but nevertheless, it continues to happen so whatever measures are being taken to stop it don't seem to be working very well.
I liked it better when the players could contain themselves till they were in the clubhouse or at least in the tunnel out of camera shot. And I also liked it a lot better when pitchers controlled their emotions on the mounds ... including, to some extent, the self-congratulatory exhuberance that some pitchers manifest.
By the way, a comment was made on Sportscenter that Prince Fielder is a leader on his team and all I could think of was ... Great ... what do the non-leaders act like in public?