Knock Apparition-Bridget's Experience?

[Beloved2018]

At Knock Ireland, one of the witnesses, Bridget Trench tried to kiss the feet of Mary, but all she felt was the wall of the church. Secondly, it is claimed that the closer one got to the apparition the more the apparition receded. These 'facts' are used by skeptics to disprove the authenticity of the apparitions at Knock and I must admit, they cause me to waver too. A hallmark of most Marian apparitions is their physicality. A few examples come to mind. At Guadalupe, Mary rearranges the roses in Juan's tilma and ties it about his neck; At Lourdes (in contrast to Knock), Bernadette is able to kiss Mary's feet; At Rue du Bac Catherine is able to recline on Mary's lap. These are just three examples.
Insights...anyone?
Thanks.

 

[John Bowen]

There are hundreds of certified documented cases of people being healed at Lourdes and other places people with no medical hope , but were healed through their faith . and the many not healed cause their faith wasn't as strong . Probably just like the sightings those who believe can see and those have a question of doubt can't . Mother Mary's rosary has brought peace and comfort and healing through out the ages . People don't need signs and wonders .You can tune into your heart where she is always is just as Jesus is too where the kingdom of God is.

 

[Beloved2018]

There are hundreds of certified documented cases of people being healed at Lourdes and other places people with no medical hope , but were healed through their faith . and the many not healed cause their faith wasn't as strong . Probably just like the sightings those who believe can see and those have a question of doubt can't . Mother Mary's rosary has brought peace and comfort and healing through out the ages . People don't need signs and wonders .You can tune into your heart where she is always is just as Jesus is too where the kingdom of God is.

But I'm asking about Bridget's experience specifically. Why couldn't she touch Mary (why only wall)? And why did the 'apparition' appear to recede the closer one got to it?