Youtuber RoltonB (with no mention of how the frog *cough* got there in the first place) sez:
Never seen nothing like this before. The video was shot entirely fortuitously. The frog is OK. There is no nails, no glue, animal abuse, etc. Later, she jumped off the bench and galloped away to the water.
He/she seems happy enough though. Contemplative. Perhaps even fixin’ to go a-courtin’.