I noticed that when I viewed my WordPress on a phone, the pictures were stretched (very annoying).
See the parts in bold, I made edits to my style.css — located in the theme folder. For example, mine was in wp > wp-content > themes > twentytwelve, file name: style.css
/* Minimum width of 300 pixels. */
@media screen and (min-width: 300px) {
.author-avatar {
float: left;
margin-top: 8px;
margin-top: 0.571428571rem;
}
.author-description {
float: right;
width: 80%;
}
.site {
margin: -15px -15px;
max-width: 500px;
max-width: 100rem;
overflow: hidden;
}
.site-content {
float: left;
width: 105%;
}
img {
/* This controls the image */
max-width: 100%;
height: auto;
}
.site-header h1,
.site-header h2 {
text-align: left;
}
.site-header h1 {
font-size: 26px;
font-size: 1.857142857rem;
line-height: 1.846153846;
margin-bottom: 0;
}
.main-navigation ul.nav-menu,
.main-navigation div.nav-menu > ul {
border-bottom: 1px solid #ededed;
border-top: 1px solid #ededed;
display: inline-block !important;
text-align: left;
width: 100%;
}
.main-navigation ul {
margin: 0;
text-indent: 0;
}
.main-navigation li a,
.main-navigation li {
display: inline-block;
text-decoration: none;
}
.main-navigation li a {
border-bottom: 0;
color: #6a6a6a;
line-height: 3.692307692;
text-transform: uppercase;
white-space: nowrap;
}
.main-navigation li a:hover {
color: #000;
}
.main-navigation li {
margin: 0 40px 0 0;
margin: 0 2.857142857rem 0 0;
position: relative;
}
.main-navigation li ul {
display: none;
margin: 0;
padding: 0;
position: absolute;
top: 100%;
z-index: 1;
}
.main-navigation li ul ul {
top: 0;
left: 100%;
}
.main-navigation ul li:hover > ul {
border-left: 0;
display: block;
}
.main-navigation li ul li a {
background: #efefef;
border-bottom: 1px solid #ededed;
display: block;
font-size: 11px;
font-size: 0.785714286rem;
line-height: 2.181818182;
padding: 8px 10px;
padding: 0.571428571rem 0.714285714rem;
width: 180px;
width: 12.85714286rem;
white-space: normal;
}
.main-navigation li ul li a:hover {
background: #e3e3e3;
color: #444;
}
.main-navigation .current-menu-item > a,
.main-navigation .current-menu-ancestor > a,
.main-navigation .current_page_item > a,
.main-navigation .current_page_ancestor > a {
color: #636363;
font-weight: bold;
}
.menu-toggle {
display: none;
}