I think the respect factor comes in the form of a print Bible being just the Bible, being the Word of God in hand; which would apply whether it were still printed on scrolls today or bound as a book. There is a measure of respect involved when some see a print Bible because they easily recognize it as the Word of God.
On the other hand, a tablet is a generic device used for many different things, capable of displaying the words from the Bible, a romance novel, a work of perversion and false religion texts; as well as mundane things such as games and recipes. When one sees a tablet they have no instant thought of respect or thoughts of the Word of God.
I believe that's the difference being brought up. It's not a matter of what medium one is reading the Word from, but in the context I mention above.
Further along, as Miss Daisy mentions, when folks are seen with a Bible in hand, when they have their Bible open and are reading, folks generally recognize what they have, what they are reading and what it represents. If someone is seen looking at a tablet or smart phone, unless one is close enough to see what is on the screen, that person could be looking at or doing a myriad of things other than reading the Bible.
A couple years ago or so a family visited our church. The teen son got is smart phone out as if to access the Bible but then proceeded to place the smart phone out of view of his parents. Throughout the rest of the service it seemed he was checking out other things, texting and who knows what else.
If a person needs to read the Bible on a tablet for visual reasons, I understand and I have no problem with that. Our church finally installed a retractable screen and video equipment so we are able to put the hymns and Scripture in big letters on the screen for the help of our many elderly folks who can no longer see the print in the hymnals or print Bibles.
Myself, even with the Scripture text on the screen, I still open my Bible and read from there as the pastor reads the text. More and more it seems the only ones who actually carry a Bible with them are those who also attend the Sunday school. We have about three people in our Sunday school who use a tablet or smart phone to access the Bible for class, otherwise everyone else has a print Bible, and there are several pew Bibles available for guests or anyone who may have forgotten their Bible that day.
In a public ceremony, where image is very important, I think an obvious Bible should be used as one pledges to carry out their duties.
As for church and other general matters, much of that is a matter of personal choice. This is where each person should examine their heart to see why they carry/use what they do. Are they carrying a tablet or smart phone because they don't want to be seen carrying an actual Bible? Are they carrying a Bible just because they want others to see them carrying a Bible? Is the tech Bible app simply the best format for them so they use it? Is the print Bible the best for their needs? If our heart is right before God in which we are using, then we are doing well. If not, then we need to correct that.