This is a very cool and rather difficult position to get used to, as I'm really starting to push the limits of "pedal-steel" licks here for you! It involves the "tri-tone" theory, wherein the seventh and third, become the third and seventh from the I to the IV chord, but more importantly, it's a very deft and acrobatic way of playing a three-note pedal steel riff on the guitar that has movable parts!
The most difficult challenge for you will be to actually maintain the pitch of the bend, while shifting the other fingers to accommodate the new chord. It's tricky at first, but as you'll see it's well worth it! It's also a great way to play what most people would think of as a "Country lick" over Blues changes, and with Blues phrasing. This is something I love to do, where we can really blend and overlap the 2 genres, Country and Blues, to come up with new and creative ideas!
Don't forget to build up your strength with these bends, and always be sure to help that bending finger along with the additional index finger right behind it! The video will tell the whole story. Have fun with it, as I'm sure this is a new one for you all!—Arlen Roth