When designing the preview, mockups of the following authors were used:  

<a href='https://ru.freepik.com/psd/frame'>Frame PSD создан(а) rawpixel.com - ru.freepik.com</a>

<a href='https://ru.freepik.com/psd/mockup'>Mockup PSD создан(а) rawpixel.com - ru.freepik.com</a>

<a href='https://ru.freepik.com/psd/mockup'>Mockup PSD создан(а) freepik - ru.freepik.com</a>