$SF _4$ has a trigonal bipyramidal structure with lone pair of electron in the equatorial position. $F - S - F$ bond angle is $101^{\circ}$.

$OSF _4$ has a $p$ character due to double bond hence bond angle is more.

In the trigonal-bipyramidal species $H _2 C = SF _4$ the $H$ atoms are located in the plane of the axial $F$ atoms. There are no lone pair in $CH _2= SF _4$ molecule.

The $F - S - F$ bond angle is $97^{\circ}$. More s character of lone pair leads to increase concentration of $p$ character of fluorine.

Thus the bond angle is more as $p$ character of fluorine atom is more as compared to $SF _4= CH _2$