Black's tenuki
It is possible for Black to ignore here. This position may also occur as a 6-3 point joseki.
In practice this sequence appears, in pro games, which is the same as if there were a black pincer stone at a (3-4 point distant low approach) and the usual variation. At this point some deviation should occur.
These are pro plays: to control
,
to kill off
is then thick.
See also 3-6 point pincers for some ideas that are rarer, in pro games anyway.