With CSS, Take a look at .message, and to make it come up after a few seconds, I am not sure :
#donor-notification {
width: 377px !important;
height: 260px !important;
background-color: transparent !important;
background-image:url('http://i.imgur.com/V50K2uP.gif') !important;
background-repeat: no-repeat !important;
background-size: initial !important;
}
#donor-notification .header {
position: absolute !important;
visibility: hidden !important;
}
#donor-notification .streamname {
visibility: hidden !important;
}
#donor-notification .message {
position: absolute !important;
text-align: center !important;
margin-top: 270px !important;
margin-left: 0px !important;
width: 400px !important;
font-size: 24px !important;
font-weight: bold !important;
font-family: Arial !important;
color: white !important;
-webkit-text-fill-color: white;
}
#donor-notification .amount {
position: absolute !important;
text-align: center !important;
margin-top: 150px !important;
margin-left: 120px !important;
width: 300px !important;
font-size: 24px !important;
font-weight: bold !important;
font-family: Arial !important;
color: white !important;
-webkit-text-fill-color: white;
}
#donor-notification .donor {
position: absolute !important;
text-align: center !important;
margin-top: 150px !important;
margin-left: 0px !important;
width: 300 !important;
font-size: 24px !important;
font-weight: bold !important;
font-family: Arial !important;
color: white !important;
-webkit-text-fill-color: white;
}
#donor-notification .title {
padding-top: 44px !important;
margin-left: 0px !important;
width: 100% !important;
float: left !important;
text-align: left !important;
}