Verizon limits MMS pictures to 350KB in size, other carriers have other limits like AT7T is 250KB so if someone from AT&T sends you picture it will be smaller than the same picture taken and sent over a Verizon phone.
Also you can press and hold on the picture and it will pop up in another window. but remember they are still goint o be much smaller that the original picture because the phones resize the picture before it is sent.
