So you want to share photos, watch videos, or play computer games on the expansive screen of your HDTV? On one hand, this is a really simple how-to: use HDMI! That, of course, isn't the whole story.

A: Many TV companies have tried to make screens that blend more seamlessly into one’s decor—the Samsung Frame (from $600), for example, resembles a simply framed piece of wall art and can shuffle ...