Looks to me like someone put clincher rim strips on a tubular rim (tubular rims do not require rim strips). Tubular base tape would extend beyond the edges, it would be very unusual for a tire to separate from the base tape in this manner, it wouldn't be cut away neatly at the valve hole, and if it were base tape you would probably see the impression of the tire's stitching in it. Could be some kind of tubular glue alternative tape like Tufo's. In any case, it should be removed and a couple coats of glue put down on the rim.

When I put glue on a new tire, I inflate it just enough so the tire twists half-way, so when I lay the tire on a table, the base tape points up - Sammyboy inflated his tire too far so when he lays it on a table the tape will be pointed out and it'll be hard to keep the glue from running down.

<tubular lore possibly BS statement> I've also read somewhere that inflating a tubular off the rim high enough to twist it all the way around like this is somehow bad for the tire... </lore>

And once again, tubulars can be mounted on a clincher wheel and pressurized to full rating for stretching purposes.