Tweeper doesn't provide direct links to videos and vines from twitter
but it still shows the preview picture provided by the original HTML
code; unfortunately the picture repeats itself, so avoid that.
+    <!-- Don't repeat background in embedded media content -->
+    <xsl:template match="div[contains(@class, 'PlayableMedia-player')]">
+        <xsl:copy>
+            <xsl:apply-templates select="@*"/>
+            <xsl:attribute name="style">
+                <xsl:value-of select="concat(@style, '; background-repeat: no-repeat')"/>
+            </xsl:attribute>
+            <xsl:apply-templates select="node()"/>
+        </xsl:copy>
+    </xsl:template>
+
     <xsl:template match="a[@data-expanded-url]" mode="enclosure">
         <xsl:copy-of select="php:function('Tweeper::generateEnclosure', string(./@data-expanded-url))"/>
     </xsl:template>
     <xsl:template match="a[@data-expanded-url]" mode="enclosure">
         <xsl:copy-of select="php:function('Tweeper::generateEnclosure', string(./@data-expanded-url))"/>
     </xsl:template>