LATEST Ecards

Who here knows how to make the (Latest Ecards) Images 100 By 100 on All Devices?!  I Changed <class="img-responsive"> to <style="width:100px;height:100px">, but that was Only a Success on my Windows Computer.  On my iPad & Phone, Those Images looked like they Became 100% Width.  But the Height Looked Okay.  :--)