Then find the following template login_main
Roughly on the line
24-
<input type="text" name="username" value="{vb:var formData.username}" class="js-login-username b-form-input__input b-form-input__input--full" placeholder="{vb:phrase {vb:var loginPhrase}}" />
<img src="images/username.png" alt="Username" /> <input type="text" name="username" value="{vb:var formData.username}" class="js-login-username b-form-input__input b-form-input__input--full" placeholder="{vb:phrase {vb:var loginPhrase}}" />
Roughly on the line
29-
<input type="password" autocomplete="off" name="password" class="js-login-password b-form-input__input b-form-input__input--full" placeholder="{vb:phrase password}" />
Add this before <img src="images/password.png" alt="Password" />
<img src="images/password.png" alt="Password" /> <input type="password" autocomplete="off" name="password" class="js-login-password b-form-input__input b-form-input__input--full" placeholder="{vb:phrase password}" />